Consumption of Nightshade Plants paper now available

Dear Readers,

Dr. Cordain's newest paper "Consumption of Nightshade Plants" is now available from our web store.

Thank you for your continued readership.

Paleo Diet Q & A: Blood Type and Diet

Q: Professor, I pulled my information from thepaleodiet.com and attributed the statement, "Paleo is truly is the world’s healthiest diet," to you, which I doubt is a stretch.

Have you gotten into any of the information about the blood-type-related nutrition info? I've only heard snippets, but I'm curious what an expert thinks of it.

Seth

A: Hi Seth,

Thanks for your support. I am currently completing a paper on nightshades, and when it is done the very next topic in the queue is my critique of the Blood Type Diet, which I have been researching and reading about for the past couple of weeks. Although I don’t want to give away the story line, I can say that the concept of four specific types of diet for the four ABO blood groups (A, B, O & AB) is not supported by the available data. However, having said that, susceptibility to disease, and the robustness of the immune response to pathogens throughout the entire GI tract, is very much related to ABO blood groups. Our group has published at least one paper on the dietary lectin/disease concept and we believe that common dietary lectins may promote certain diseases (allergies, autoimmune disease) while simultaneously promoting chronic low level inflammation. However, little evidence in either humans, animals or tissues point in the direction that dietary lectins elicit disease symptoms exclusively via interaction with ABO antigens. Additionally, of the hundreds of plant lectins that have been identified, only a very select few have been demonstrated to bind gut tissue. Hence, most dietary lectins are benign, simply because they cannot penetrate the gut barrier.

Cordially,
Loren Cordain, Ph.D., Professor

Paleo Diet Q & A - Sprouted Legumes

Q: Hi, the Paleo Diet makes a lot of sense to me and I very much appreciate the research that's gone into it. However, am I right in thinking that any diet we are adapted to may nevertheless not be an ideal diet? We adapted to a diet that enabled us to be healthy enough to live long enough to reproduce healthy enough offspring.

If I understand correctly, couldn't certain foods could make that basic diet even healthier? For example, I have The Paleo Diet for Atheletes out from the library right now and I see that you believe that the life of an athlete requires departure from a strict paleolithic diet. Couldn't properly treated grains and legumes be beneficial additions to the diet? (i.e. soaked/sprouted to reduce/eliminate anti-nutrients?)

I am waiting to receive The Paleo Diet from the library (I'm on a long waiting list, which is good news I guess!) so maybe you address this issue in the book, in which case, I apologize. But if not, I would appreciate knowing your views on soaking/sprouting grains and legumes, and the reasons behind those views.

Thanks so much,
Zena

A: Dear Zena, first of all - thanks for supporting our work.

Lectins, one of the known antinutrients in cereal grains and legumes1, have been demonstrated to exert several deleterious effects upon human physiology1, (especially for those with autoimmune diseases) by increasing intestinal permeability2. Their function is to protect the plant against attacks by plant-eating animals by using several toxic substances, such as lectins3. There is a growing body of evidence showing that both the root and the sprout of wheat kernels have significant amounts of wheat germ agglutinin (WGA), one of the most studied lectins. Indeed, WGA originates in the wheat kernel, especially during germination and growth4, and the highest concentrations are found in young plant roots, seeds, and sprouts.

Lectins are resistant to digestive enzymes, and are found intact in peripheral circulation, as shown by Wang et al (1998)5. Furthermore, they are deposited in the internal organs6.

As stated by Pusztai et al7, lectins are heat stable, and normal cooking does not completely eliminate these toxic compounds unless they are pressure cooked8-11. The best way to reduce lectins' adverse health effects is to limit their intake.

In addition, saponins - another type of toxic/antinutritive compound - exist in legume sprouts. Saponins have been shown to affect the gut barrier and by extension immune system function12. They may also increase the risk of autoimmune diseases in genetically susceptible individuals13. Soaking, sprouting or cooking legumes, does not reduce their saponin content14, 15.

In addition, a peptide fraction from gluten proteins called gliadin is found in wheat. Gliadin is resistant to digestive enzyme degradation16, arrives intact when it comes into contact with intestinal epithelial cells17, and increases intestinal permeability. Increased intestinal permeability may be at the root of autoimmune diseases such as Celiac Disease and Type 1 Diabetes13.

Phytate, the main form of phosphorus storage in many plants (especially bran and seeds) is classified as an antinutrient because is a chelator of iron, magnesium, calcium and zinc1. Phytate ingestion inhibits the intestinal absorption of those minerals. Phosphorus from phytate is unavailable to humans, as we do not produce the phytase enzyme necessary to break down phytate - unlike ruminants, who do produce phytase, and are able to digest phytate18. Yeast fermentation in bread reduces phytate content19. Furthermore, addition of ascorbic acid counteracts the inhibitory effects of phytate upon iron absorption20. Soaking and fermentation reduces the phytate content of grains and legumes as indicated in several studies21, 22, 23, 24.

Having said that, Dr. Cordain in his first book talks about the 85:15 rule, where he explains that 85% of caloric intake from modern paleolithic-like foods is still more healthy than the typical western diet, where more than 70% of caloric intake comes from foods introduced in the human food chain after the agricultural revolution25.

The bottom line is that our metabolism is perfectly adapted to the nutrition that shaped our genome during million of years of evolution. Therefore, any nutrient introduced after the agricultural revolution may not be compatible with our ancient genome. We believe that anyone engaged in athletic activities could do very well on a diet based on 85% paleolithic nutrients, which are preferable to the nutrients found in the typical western diet.

I hope this is helpful.
Maelán Fontes

References:

Cordain L. Cereal Grains: Humanity’s Double-Edged Sword. World Rev Nutr Diet. Basel, Karger,
1999, vol 84, pp 19–73.Cordain L. et al. Modulation of immune function by dietary lectins in rheumatoid arthritis. British
Journal of Nutrition (2000), 83, 207–217.Chrispeels, M.J. & Raikel, N.V. (1991) Lectins, lectin genes, and their role in plant defense. Plant Cell 3, 1-9.Miller, R., & Bowles, D. (1982). A comparative study of the localization of wheat-germ agglutinin
and its potential receptors in wheat grains. Biochem. J., 206, 571-576.Wang Q, Yu LG, Campbell BJ, Milton JD, Rhodes, JM. Identification of intact peanut lectin in peripheral
venous blood. Lancet 1998;352:1831-32.Caron, M. & Steve, A.P. (2000) Lectins and Pathology, Taylor & Francis, London. Pusztai A and Grant G. Assessment of lectin inactivation by heat and digestion. From Methods
in Molecular Medicine. Vol 9 Lectin methods and protocols. Edited by J M Rhodes and J D Milton Humana
Press Inc. Totowa, NJ.Grant G, More LJ, McKenzie NH, Pusztai A. The effect of heating on the haemagglutinating activity
and nutritional properties of bean (Phaseolus vulgaris) seeds. J Sci Food Agric 1982;33: 1324-1326.Boufassa C, Lafont J, Rouanet J M, Besancon P 1986 Thermal inactivation of lectins (PHA)isolated
from Phaseolus vulgaris. Food Chem 20 295-304.Buera M P, Pilosof A M R, Bartholomai G B 1984 Kinetics of trypsin inhibitory activity loss in
heated flour from bean Phaseolus vulgaris. J Food Sci 49 124-126.Collins J L, Beaty B F 1980 Heat inactivation of trypsin inhibitor in fresh green soybeans and
physiological responses of rats fed the beans. J Food Sci 45 542-546.Patel B, Rober S, Sporns P, et al. potato glycoalkaloid adversely affect intestinal permeability
and aggravate inflammatory bowel disease.Visser J, Rozing J, Sapone A et al. Tight junctions, Intestinal permeability and Autoimmunity.
Ann. N. Y. Acad. Sci. 1165: 195-205 (2009).Ruiz RG, Price K, Rose M, Rhodes M, Fenwick R. A preliminary study on the effect of germination
on saponin content and composition of lentils and chickpeas. Z Lebensm Unters Forsch 1996;203:366-369.Ruiz RG, Price KR, Arthur AE, Rose ME, Rhodes MJ, Fenwick RG. Effect of soaking and cooking on
the saponin content and composition of chickpeas (Cicer arietinum) and lentils (Lens culinaris).
J Agric Food Chem 1996;44:1526-1530.Shan L, Qiao SW, Arentz-Hansen H, et al. Identification and Analysis of Multivalent Proteolytically
Resistant Peptides from Gluten: Implications for Celiac Sprue. J Proteome Res. 2005 ; 4(5): 1732–1741.Drago S, Asmar R, Di Pierro M, et al. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac
intestinal mucosa and intestinal cell lines. Scandinavian Journal of Gastroenterology,
2006; 41:408/419.Klopfenstein, TJ et al. "Animal Diet Modification to Decrease the Potential for Nitrogen and
Phosphorus Pollution". Council for Agricultural Science and Technology 21.Reinhold JG. Phytate destruction by yeast fermentation in whole wheat meals. J Am Diet Assoc 1975;66:38-41.Hallberg L, Brune M, Rossander L. Iron absorption in man: ascorbic acid and dose-dependent inhibition
by phytate. Am J Clin Nutr 1989;49:140-4.Chen LH, Pan SH. Decrease of phytates during germination of pea seeds (Pisium Sativa). Nutr Rept Int.
1977;16: 125-131.Walker KA. Changes in phytic acid and phytase during early development of phaseoleus vulgaris beans.
Planta 1974;116:91-98Bain, J. M., Murcer, F. V.: Changes in phytic acid and acid-soluble phosphorus in maturing pinto beans.
J. Sci. Fd. Agric. 20, 82–84 (1966).Jennings, A. C., Morton, R. K.: Changes in nucleic acids and other phosphorus-containing compounds of
developing wheat grain. Aust. J. Biol Sci. 16, 332–341 (1963b).Cordain L, Eaton SB, Sebastian A, et al. Origins and evolution of the western diet: health implications
for the 21st century. Am J Clin Nutr 2005;81:341–54.

Report Issued on the 2010 Dietary Guidelines for Americans

by Patrick Baker, Editor

On June 15, 2010 the US Federal Government announced the release of the Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, a solicitation for written comments on the report, and an invitation for testimony at a public meeting to be held on July 15, 2010 in Washington D.C. Links to this announcement, the report, and instructions for submitting written comments or attending the public meeting are available at the Dietary Guidelines for Americans web site (www.DietaryGuidelines.gov).

Federal legislation requires that the most recent edition of the guidelines (last published in 2005) be reviewed, updated if necessary, and published every five years. The current report contains the recommendations of the 2010 Dietary Guidelines Advisory Committee (DGAC) to the Secretaries of Agriculture and of Health and Human Services for use in updating the Guidelines.

In the introduction, the 2010 DGAC report states that two-thirds of the American public is overweight or obese. It goes on to say that "Americans are making dietary choices in a highly obesogenic environment and at a time of burgeoning diet-related chronic diseases affecting people of all ages, ethnic backgrounds, and socioeconomic levels. The DGAC considers the obesity epidemic to be the single greatest threat to public health in this century."

The introduction goes on to discuss the role of diet and physical activity in attenuating the risk of chronic diseases, as well as identifying population groups of particular concern. These include: children, pregnant and lactating women, and older adults.

Dr. Cordain was asked to comment on the report, and stated "I really don't see how these ‘new’ recommendations vary substantially from prior USDA Food Guidelines." Cordain states that the recommendations to consume whole grains and skim milk "obviously vary from the human ancestral diet, and upon closer scrutiny, these two foods are not necessarily healthful."

Dr. Cordain’s cites evidence from his book The Paleo Diet, as well as his and other published research, that whole grain products frequently may contribute to an elevated glycemic load because of the quantity of total grains the USDA recommends (8 ounces per day, equivalent to 8 slices of bread). Wheat in particular is problematic because it contains the storage protein gliadin, shown to increase intestinal permeability in celiac patients as well as in healthy persons.

Cordain notes that increased intestinal permeability promotes passage of a gut borne bacterial substance called lipopolysachharide into the bloodstream, producing a low-level chronic state of inflammation called endotoxemia (see Maelán Fontes’ article on Type 2 Diabetes and Endotoxemia). Endotoxemia likely underlies many chronic disease states, particularly cardiovascular disease and a number of autoimmune diseases, according to Cordain.

Dr. Cordain goes on to say that, "In the U.S. alone, it is estimated that 1 in 100 people or about 3 million US citizens have celiac disease. It is irresponsible to make across-the-board dietary recommendations to the entire population given the high incidence of celiac disease."

Cordain notes that while skim milk is promoted by the USDA because it contains much lower concentrations of saturated fat, it has been shown to be highly insulinotropic – "meaning that it raises blood insulin concentrations, similar to eating candy or a chocolate chip cookie." Dr. Cordain states that, "Work from our laboratory substantiated this effect for both skim and whole milk. In a recent study of young boys, they became insulin resistant after seven days on a high milk diet, compared to seven days on a high meat diet. This study has not been replicated in adults, but there is no reason to believe that the response would vary." Consumption of milk elevates a hormone called IGF-1 - which increases growth in children, resulting in an increased adult stature. However, says Cordain, "it also increases the risk for breast, colon and most particularly prostate cancer."

The Dietary Guidelines Advisory Committee is accepting written comments on the report until July 15, 2010. The public meeting to solicit oral comments on the report will be held on July 8, 2010, starting at 9:00 am EDT. Details are available at the Dietary Guidelines for Americans web site (www.DietaryGuidelines.gov).

Paleo Diet Special Report: Chia Seeds

Dear Readers,

The following is an excerpt from a special report authored by Dr. Cordain on Chia seeds. The full report is available in our newsletter, The Paleo Diet Update, Volume 6 Issue 7.

Q: Are there any negative effects associated with chia seeds which would make them inappropriate in The Paleo Diet?

Thank you.

A: Good question. I would imagine that many of our readers have never even heard of chia seeds much less eaten them. Chia seeds (Salvia hispanica L.) are a member of the Labiatae plant family and are native to southern Mexico and northern Guatemala. The seeds are small, oval shaped; either black or white colored and resemble sesame seeds. These seeds were cultivated as a food crop for thousands of years in this region by the Aztecs and other native cultures. Chia seeds can be consumed in a variety of ways including roasting and grinding the seeds into a flour known as Chianpinolli which can then become incorporated into tortillas, tamales, and various beverages. The roasted ground seeds were traditionally consumed as a semi-fluid mucilaginous gruel (Pinole) when water is added to the flour. In post-Columbian times the most popular use of chia flour was to make a refreshing beverage in which the ratio of seeds to water is decreased, thereby resulting in a less gelatinous consistency to which lemon, sugar or fruit juice are added. The sticky consistency of chia seed Pinole or chia beverages comes from a clear mucilaginous, polysaccharide gel that remains tightly bound to the seeds. This sticky gel forms a physical barrier which may impair digestion and absorption of fat from the seed4 while also causing a low protein digestibility.

In the past 20 years a revival of interest in chia seeds has occurred primarily because of their high fat content of about 25-39% by weight, of which 50-57% is the therapeutic omega 3 fatty acid and alpha linolenic acid (ALA). In the past 10 years chia seeds have been used as a foodstuff for animals to enrich their eggs and meat with omega 3 fatty acids. So I wholeheartedly approve of feeding chia seeds to animals and then eating the omega 3 fatty acid enriched meat or eggs of these animals.

How about feeding chia seeds to humans – should we consume chia seeds because of their high omega 3 fatty acid (ALA) content? The Table below shows the entire nutrient profile of chia seeds. At least on paper, it would appear that chia seeds are a nutritious food that is not only high in ALA, but also is a good source of protein, fiber, certain B vitamins, calcium, iron and manganese.

Unfortunately, the devil is always in the details...

Welcome to The Paleo Diet Blog!

The Paleo Diet--the world’s healthiest diet--is based on the simple understanding that the best human diet is the one to which we are best genetically adapted. It is supported by documented scientific evidence and by real-life improvements, even triumphs, of people winning their personal health battles.

The Paleo Diet is based upon the life work of Dr. Loren Cordain. Dr. Cordain is widely acknowledged as a leading expert on the diet of our Paleolithic ancestors. In numerous publications in the world's best scientific journals, he has documented the dramatic health benefits of eating a diet consistent with human genetic evolution and our ancestral, Paleolithic diet. Learn how a diet based on lean meats, seafood, fresh fruits, and fresh vegetables can lead to ideal body weight, optimum health, and peak athletic performance.

This concept represents the "unified field theory" of nutrition that has until now been lacking. The discipline of human nutrition previously had no orienting paradigm to guide research and inquiry, and as such was an immature science. In contrast, cosmology has the big bang theory, which orients all thought regarding the origins of the universe, and geology has continental drift and plate tectonics, which universally guide research into the origins of earth's land mass. In biology, the fundamental, guiding principle is Darwin's theory of evolution through natural selection, which provides a template for the creation of life on earth.

It has only been in the last two decades that a few enlightened scientists have realized that this principle also represents the basic biological principle which determines the nutritional requirements of any organism - including humans. Our genes were shaped by our ancestors' environment, including our nutrtional requirements. Because what we eat today is so far removed from the diet of our hunter-gatherer ancestors, a discordance exists between our genes and our diet, and this factor represents the underlying reason why we are so sick and overweight as a society.

Dr. Cordain has authored three pioneering books that provide specific applications of The Paleo Diet for general health and nutrition, specifically for athletes, and for curing acne.

The Paleo Diet provides the background and basis for the optimally healthful diet. It has been highly praised by researchers, scientists, and readers from all over the world.

The Paleo Diet for Athletes, written by Dr. Loren Cordain and world-class fitness trainer Joe Friel, provides detailed information on how endurance athletes can improve performance, recovery, and health by eating a slightly modified version of the Paleo Diet.

The Dietary Cure for Acne represents the first real cure--not a treatment--a real solution to this pervasive skin disease. It is a natural acne diet program, based on recent research.

We also offer numerous programs designed to help people address particular nutritional and health needs. These programs can enable you to achieve your health goals whether you seek to:
permanently free yourself from acneimprove your athletic performanceenjoy a longer, healthier, more active lifelose weight without dieting and exercise,reduce or eliminate your risk of diseases, including cancer, heart disease, diabetes, and the vast majority of all chronic degenerative diseases that affect humanityFor more information about our team and our products please visit our Paleo Diet web site as well as our Dietary Cure for Acne web site.

You may post comments and questions at the end of most blog posts. Scroll down to the end of a post, type your comments in the text area under the title Post a Comment, and click the Post Comment button.

Audio Interviews with Dr. Cordain

Dear Readers,

A collection of audio interviews with Dr. Cordain (MP3 format), including his March 30, 2010 guest appearance on Seattle's The Soul's Edge radio program, have been published on our web site. Visit our web site to download the recordings.

Blood Type and Diet Newsletter Article

Dear Readers,

Dr. Cordain's article "A Critical Examination Of Blood Type Diets" was published in a recent issue of our weekly newsletter The Paleo Diet Update (Vol. 6 Issue 14). If you're not already a subscriber you may purchase this informative article from our web store. Past issues of our newsletters are available for purchase individually, or as part of the entire archive.

Thank you for your continued readership.

Ishi: America's Last Known Hunter-Gatherer

by Patrick Baker

Imagine being the last of your kind and entering a world that is nothing like the world your grandparents knew. What if you could no longer live in the homeland that had sustained your ancestors for centuries? This is exactly what happened nearly a century ago for a Native American man known to the modern world as "Ishi."

Ishi ("man" in his native Yana language) was believed to be the last of the Yahi people, and is believed to be the last Native American to have lived the majority of his life outside of American culture as it existed in 1911. Ishi was the name given to the last known hunter-gatherer in America by Alfred Kroeber, an anthropologist at the University of California at Berkeley in 1911.

Ishi shown with anthropologist A.L. Kroeber in 19111
Dr. Cordain has been researching Ishi intensely for the past six months, having been first introduced to Ishi by his father at about 11 years of age. Dr. Cordain stated that "I now believe I have an answer to Ishi's final two to three years of existence" in his ancestral home on Deer Creek, located east of present day Los Molinos, California - before his appearance in October, 1911 at a slaughter house in Oroville, California.

Kroeber stumbled into Ishi's life following his "death walk" from his hunter-gatherer home on Deer Creek to the slaughter house near Oroville. Kroeber wrote of and exploited this Native American's life and culture before Ishi’s death in 1916 from tuberculosis.

Cordain states that "sleuthing via Google Earth and the early records of Dr. Kroeber in the academic literature has given me insight into the exact location of his final 'village' of residence, and how he spent the last two to three years of his life with his paralyzed mother at another location on Deer Creek." Historically, this site was known only to the long-dead Kroeber and his colleagues. Cordain states that "modern anthropologic and forensic examination of this site would help to clarify and demystify the legend of Ishi."

Dr. Cordain believes that eventual carbon dating of this site - once verified and reexamined - will reveal the missing two to three years of Ishi’s life before he became known to the world of 20th century America. Cordain has compiled his information and will contact the appropriate members of the California Anthropological community before deciding how to proceed.

Cordain’s research and writings indicate that a contemporary diet that precisely mimics hunter-gatherer diets is "obviously impossible, as most of us don’t have unlimited access to wild game and plant foods." However, Cordain’s studies indicate that "our health, well being and mental state improve, and we can emulate Ishi's personality, psychological state and health" by consuming fresh fruits, vegetables, lean meats and seafood, as documented in his book The Paleo Diet. Dr. Cordain’s dietary recommendations in The Paleo Diet include avoiding processed foods, grains, refined sugars, refined vegetable oils, and salted foods.

Dr. Cordain goes on to say that "Ishi's story is heart-wrenching, sad, warm, but human above all else. His spirit, optimism and love of life - despite the awful events which sealed his fate - represent a truly remarkable and final tale" of the hunter-gatherer lifestyle as it was once practiced by Native Americans and other indigenous peoples. Unfortunately, much of Ishi's life will remain undocumented and unknown, and, according to Dr. Cordain, "the available historical, archaeological and forensic evidence about his final days on Deer Creek as America’s last known hunter-gatherer are vaguely understood and highly speculative."

For many of our readers, the story of Ishi may be unknown, and lost in the fog of a long forgotten history our great-grandparents knew - particularly those among us who lived with Native American inhabitants of this continent, after the American population of European descent had settled in the American West.

References:
Heizer, Robert F. (Editor), Kroeber, Theodora (Editor). Ishi the Last Yahi: A Documentary History. University of California Press, 1981.Kroeber, Theodora. Ishi in Two Worlds: A Biography of the Last Wild Indian in North America. Deluxe Edition. University of California Press, 2004.Starn, Orin. Ishi's Brain: In Search of America's Last "Wild" Indian. W.W. Norton & Co., 2005.DVD Documentary. The Last Yahi (2002). Linda Hunt (Vocals), Jed Riffe (Director), Pamela Roberts (Director)

Lysozyme from Egg Whites Article

Dear Readers,

This past week our newsletter (The Paleo Diet Update, volume 6, issue 4) featured an article by Dr. Cordain on Lysozyme and Egg Whites, and autoimmune disease. Readers who are not yet newsletter subscribers may obtain a free subscription on our web site to The Paleo Diet Update.

Readers who would like to obtain a copy of volume 6, issue 4 of The Paleo Diet update may purchase a copy of this and other back issues from our web store.

Paleo Diet Q & A - Epigenetics, Flaxseed Oil

Epigenetics

Q: What do you think about epigenetics? Many scientists (in Germany) believe that the concept of the Paleo Diet is no longer tenable.

Thanks a lot, Michael

A: Dear Michael,

Epigenetics is defined as the science studying changes in phenotype or gene expression by mechanisms other than changes in DNA nucleotide sequence1. The phenotype is someone's appearance which it's determined by the genotype (stable and heritable) and the environment (nutrition and other lifestyle factors) which give place to the epigenotype (heritable, labile and rapid)1. Epigenetic changes are controlled, among other mechanisms, by methylation and histone modification. Altered methylation pattern and histone modification may lead to increased susceptibility to disease. E.G. cancer is associated to generalized hypomethylation and localized promoters hypermethylation1. Histone manipulation may also increase or decrease disease susceptibility2.

Both, methylation and histone manipulation are under the control of dietary substances. For example, methylation depends on SAMe availability, which in turn is influenced by vitamin B6, vitamin B12 and folate intake3, and long chain polyunsaturated fatty acids such as DHA4. On the other hand, certain substances such as garlic, horseradish, fiber, blueberries, apple, onion, nuts, berries, red grapes, broccoli, etc. are known nutrients involved in histone modification2.

The Paleo Diet is rich is all of these nutrients5, hence it may exert positive effects upon epigenetics machinery leading to decreased disease susceptibility. Decreased availability of micronutrients is associated to disease severity, probably, through complex epigenetic mechanisms, and supplementation could improve those symptoms3. Improved epigenetic is influenced by metabolic programming during foetal and early life. These two periods are crucial for the developing newborn and future adult's health. Hence, The Paleo Diet may confer protection against several diseases improving the epigenetic programming.

We hope this is helpful.

Maelán Fontes Villalba
Pedro Carrera Bastos

References:

van Vliet J, Oates NA, Whitelaw E. Epigenetic mechanisms in the context of complex diseases. Cell Mol Life Sci. 2007 Jun;64(12):1531-8.Delage B, Dashwood RH. Dietary manipulation of histone structure and function. Annu Rev Nutr. 2008;28:347-66.Kemperman RF, Veurink M, van der Wal T, Knegtering H, Bruggeman R, Fokkema MR, Kema IP, Korf J, Muskiet FA. Low essential fatty acid and B-vitamin status in a subgroup of patients with schizophrenia and its response to dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. 2006 Feb;74(2):75-85.Muskiet FA, Kemperman RF. Folate and long-chain polyunsaturated fatty acids in psychiatric disease. J Nutr Biochem. 2006 Nov;17(11):717-27.Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O'Keefe JH, Brand-Miller J. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr. 2005 Feb;81(2):341-54.Kemperman RF, Veurink M, van der Wal T, Knegtering H, Bruggeman R, Fokkema MR, Kema IP, Korf J, Muskiet FA. Low essential fatty acid and B-vitamin status in a subgroup of patients with schizophrenia and its response to dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. 2006 Feb;74(2):75-85.

Flaxseed Oil

Q: I recently visited family and my brother is a new advocate of the paleo diet. For breakfast he made us "fakecakes" which had about 1-2 tablespoons of flaxseed in them that he ground in a coffee grinder. I had few a questions regarding the use of flaxseed in the Paleo Diet.

First, why are flaxseeds ok in the Paleo Diet but other grains (seeds) are not? My understanding for eliminating grains from the diet is the toxins that they contain, but flaxseed contains large amounts of cyanogenic glycosides, producing up to 139 mg/kg of hydrogen cyanide in raw human-grade flaxseed. I am sure flaxseeds are processed somehow before selling them but I don't know what process that is or what effect it has on the HCN concentration.

So, secondly...do you know of any studies on the amount of HCN in meals containing ground flasxseed and the chronic oral exposure of those amounts on humans? My understanding here is the HCN that isn't hydrolysed to formic acid in the stomach and doesn't bind to hemoglobin is converted to thiocyanate which hinders thyroid function.

Thank you for your time and any information you can supply.

Sincerely,
Tim

A: Hi Tim,

We think your thoughts are on the right track.

When Dr. Cordain wrote The Paleo Diet book, the advice to consume flaxseed oil was an attempt to balance the increased omega-6/omega-3 fatty acid ratio due to the exaggerated intake of omega-6 vegetable oils, especially linoleic acid, in the typical western diet.

Nevertheless, animal foods (fish, muscle meat and organs from wild animals) are good sources of w3 fatty acids. Therefore, when people eat these foods regularly along with vegetables and nuts, and avoid vegetable oils (especially oils rich in Linoleic Acid – Omega 6), they get a balanced intake of omega 3, omega 6, monounsaturated and saturated fatty acids. In this situation, there is no need for flax seeds to provide Omega 3 fatty acids and balance the Omega 3/Omega 6 ratio.

Here are some facts that support the notion that animal foods, vegetables and nuts provide the necessary Omega 6 and Omega 3 fatty acids in the right proportion:

Hunter-gatherers do not eat ALA from seeds or vegetable oils.Nuts, green leafy vegetables and animal foods contain ALA.The conversion of ALA to EPA+DHA is limited, due to low delta-6 and delta-5 activity, although ALA is highly oxidized (twice that of LA) (see paper by Freemantle et al). This means that at some point in history we included preformed sources of EPA and DHA and still need to do so. Animal foods (especially brain from wild ruminants and fish) are very good sources of these fatty acids.The essentiality of LA & ALA in human metabolism has been questioned (see paper by Le et al.), as we relied almost on LCPUFA (Arachidonic Acid, EPA and DHA) during the Palaeolithic era (see Dr. Cordain’s papers on that here and here). Moreover, there is already some evidence showing that human metabolism could re-convert AA and DHA into LA and ALA respectively, hence AA and DHA would be the true essential fatty acids.The possible toxicity from seeds and vegetable oils (HCN, saponins, lectins).They are not used by current HG societies, and these populations show no signs of western disease, so this means that flax seeds are not necessary.The well known positive health effects of fish oil supplementation (among other factors to improve omega-6/omega-3 ratio) in contrast with some possible adverse effects of flaxseed oil (like the epidemiological evidence that points towards increased risk of prostate cancer with flax oil consumption – see paper by Brouwer et al).

The bottom line from an evolutionary perspective is that flax seeds and/or flaxseed oil would not have been consumed by pre-agricultural humans. However, having said that, hunter gatherers always would have preferentially sought high oil plant foods as per optimal foraging theory. But, most high fat plant foods contain high MUFA (with the exception of coconut and palm oils).

Hope this helps,
Maelán Fontes Villalba

Additional reading: Effectiveness of different processing methods in reducing hydrogen cyanide content of flaxseed, Feng, et al.

Protein Intake for Pregnant Women

by Loren Cordain, Ph.D., Professor

Q: Hello Dr. Cordain

I would like to know if you could direct me to any research that indicates what amounts of protein are necessary for pregnant women who live the Paleo Diet way. I am in my third trimester with my first child and have been living Paleo since I first heard you lecture on it back at Boulderfest before your book came out. I have been the picture of health and my pregnancy has been very easy. I am finding that my protein and fat requirements are significantly higher.

Is there any research you could direct me to regarding protein requirements for pregnancy based on trimester?

Thank you very much and I look forward to hearing from you.

Best Regards,
Lynda

A: Hi Lynda,

This question has come up before and the bottom line is that your probably should increase your fat and carbohydrate consumption, and limit protein to about 20-25% of energy, as higher protein intakes than this may prove to be deleterious to mother and fetus for a variety of physiological reasons. In my next book, I have devoted a chapter to maternal nutrition before, during and after pregnancy and why protein must be limited during pregnancy.

My colleague John Speth (an anthropologist) at the University of Michigan wrote a paper on protein aversion in hunter-gatherer women during pregnancy. Listed below is the abstract: (note the 25% protein energy ceiling!!!)

"During seasonal or inter-annual periods of food shortage and restricted total calorie intake, ethnographically and ethnohistorically documented human foragers, when possible, under-utilize foods that are high in protein, such as lean meat, in favour of foods with higher lipid or carbohydrate content. Nutritional studies suggest that one reason for this behaviour stems from the fact that pregnant women, particularly at times when their total calorie intake is marginal, may be constrained in the amount of energy they can safely derive from protein sources to levels below about 25% of total calories. Protein intakes above this threshold may affect pregnancy outcome through decreased mass at birth and increased perinatal morbidity and mortality. This paper briefly outlines the evidence for the existence of an upper safe limit to total protein intake in pregnancy, and then discusses several facets of the issue that remain poorly understood. The paper ends by raising two basic questions directed especially toward specialists in primate and human nutrition: is this protein threshold real and demographically significant in modern human foraging populations? If so, does an analogous threshold affect pregnant female chimpanzees? If the answer to both of these questions is yes, we can then begin to explore systematically the consequences such a threshold might have for the diet and behaviour of early hominids."2

The physiological basis for this aversion stems from a reduced rate of urea synthesis during pregnancy that is evident in early gestation1 as well as increases in the stress hormone cortisol3. Hence, pregnant women should include more carbohydrate and fat (i.e. fattier meats) in their diets and limit dietary protein to no more than 20-25% of their total caloric intake.

Hope this helps!
Loren Cordain, Ph.D., Professor

References:
Kalhan, S. Protein metabolism in pregnancy. Am J Clin Nutr 2000;71 (suppl): 1249S-55S.Speth JD. Protein selection and avoidance strategies of contemporary and ancestral foragers: unresolved issues. Philos Trans R Soc Lond B Biol Sci. 1991 Nov 29;334(1270):265-9; discussion 269-70.Herrick, K., Phillips, D. I. W., Haselden, S., Shiell, A. W., Campbell-Brown, M., Godfrey, K. M., 2003. Maternal consumption of a high-meat, low-carbohydrate diet in late pregnancy: relation to adult cortisol concentrations in the offspring. J. Clin. Endocrinol. Metab. 88(8):3554-3560.

Paleo Diet Q & A - Whey Protein

Q: Could you please provide some details on the benefits/detriments of whey protein supplementation? I am a weight trainer/powerlifter and supplement with whey protein, which is currently touted as the best/most health-conscious choice there is. I have read in your newsletter about the inflammatory aspects of dairy products - is whey protein included in this? Is it better or worse than other dairy products?

Many people interested in the Paleo Diet who are also into strength training and fitness would be interested in your thoughts on this. Any pointers re: inflammation and supplementation of protein would be very well received. Thank you, in advance.

Best regards,
Karl

A: Dear Karl,

Unfortunately, at this point, most of the research has focused on the beneficial effects of whey. It basically revolves around whey's high BCAA content, its use as a post-workout recovery drink ingredient, and its capacity – due to cysteine – to increase Glutathione, a powerful endogenous antioxidant enzyme.

Nevertheless, we believe that whey protein can have some potential adverse effects, because it greatly elevates insulinemia - although it can be therapeutic for diabetics in the short term. We suspect that whey protein could be detrimental long term, as hyperinsulinemia can down-regulate the insulin receptor and lead to insulin resistance. Insulin resistance underlies the Metabolic Syndrome, and is implicated in various other diseases, such as Acne, Alzheimer, various cancers, Coronary Heart Disease, Myopia, PCOS, etc.).

But to be completely sure, we would need intervention studies with whey protein with a relatively long duration in people genetically prone to insulin resistance, or who are in fact insulin resistant.



Also, there is the matter of hormones in milk: estrogens, DHT precursors, Insulin, IGF-1 and the hormone Betacellulin (BTC), which Dr. Cordain has discussed in a previous edition of this newsletter. These are some of the possible mechanisms for which there is repeated epidemiological evidence associating milk consumption with some cancers - especially Prostate Cancer.

We know that these hormones are present in milk and - in the case of BTC - it is present in whey too. Nevertheless, the real content of all these hormones in commercial milk-derived products is an open question that deserves proper and urgent study. So while we don’t know for sure, and since and we have alternatives, I would follow the old saying: do no harm!

Finally, if you have an auto-immune disease or allergy to Beta Lacto Globulin (protein that exists in bovine milk, but nonexistent in human milk) I would stay away from whey. Whey contains not only Beta Lacto Globulin, but also Bovine Serum Albumin. Some peptides from this protein have structural homology with peptides from our own tissues, and BSA has been implicated in Multiple Sclerosis, Rheumatoid Arthritis and Type 1 Diabetes.

In conclusion, I would follow the evolutionary template until all these issues are resolved. which states that recently introduced foods may have potential adverse effects to humans, especially long term. Non-human milk was only introduced in the human diet ~10,000 years ago. Therefore, given the potential health hazards of milk that science is revealing, I would use another protein source. Lean meat and seafood are very good sources of BCAA. If you want a protein drink immediately after strength training to speed recovery and increase muscle mass, I would suggest ~9 grams of essential amino acids, along with a banana.

I hope this helps.

Cordially,
Pedro Bastos

Editor's note: the following blog posts also discuss whey protein:
Q: I started the program and I was wondering if Whey Protein or protein powder in general is against the diet?
Q: I like drinking protein shakes in the morning, but I noticed some of the protein sources in my protein shake are made from milk or dairy products. Is there an alternative that is available in the market place?
Q: I am just trying to figure out your feelings and thoughts on protein powders.
Additional reading: Hyperinsulinemic diseases: more than just Syndrome X.

The Paleo Diet in the News

Dear Readers,

The Paleo Diet and Dr. Cordain's work have been cited in recent articles in the following media:
Mail Tribune, Medford, Oregon
Daily News, Redbluff, California
The Ledger, Lakeland, Florida
The Press of Atlantic City
A Sweet Life: An interview with a Type 1 Diabetic
Netstrife News - Rapid Weight Loss on the Paleolithic Diet (click on the article to make the pop-up go away).
Medscape - Does Diet Really Affect Acne?
Total Health Breakthroughs - Beating Obesity, The Old-Fashioned Way
Robb Wolf discusses The Paleo Diet in his podcast The Paleolithic Solution. Robb is a former student of Dr. Cordain's, and an advocate of Cordain's work in paleolithic nutrition.
Psychology Today - features an article on The Paleo Diet in their June edition (print), and their own paleolithic nutrition Q &A referencing Dr. Cordain's work on their blog. PT first wrote about Dr. Cordain's work in paleolithic nutrition in 1997!
WBUR.org (Boston NPR affiliate)
Westword
San Jose Mercury News
ArgusLeader.com
AnnArbor.com
ESPN - main article, expanded articleThe Colbert Report - interview with John Durant
The Denver Post
National Post
Voice of AmericaMacleans
Politics DailySun-SentinelAFPSpiegel OnlineIndependent OnlineThe Times OnlineThe New York TimesThe Washington PostAOL's thatsfit.comBook publishing news site GalleycatThe ExaminerMedscapeHuffington Post

Type 2 Diabetes and Endotoxemia

by Maelán Fontes

Currently there’s an epidemic of type 2 diabetes (T2D) worldwide, especially in Westernized countries. T2D is characterized by persistent elevated glucose levels due to disrupted insulin action or an alteration in pancreatic insulin production1.

It was estimated that 171 million people were suffering from T2D in 2001, with a total overall population prevalence of 6%. More alarming is the fact that in Caucasian adolescents 4% suffer from T2D and 25% are glucose intolerant1. However, T2D prevalence in hunter-gatherer societies is low2-6, and even nonexistent in the island of Kitava in Trobiand Islands in Papua New Guinea3.

Genetics does not seem to explain the difference, because when these populations are Westernized they suffer even more from diseases of civilization such as T2D, obesity, myocardial infarction and stroke among others7-10 than original Western populations. Furthermore, there’s evidence showing that hunter-gatherer populations can reverse T2D when they are resettled in their ancient habitat8, a fact that has been demonstrated in two recent clinical trials conducted on Western populations11, 12.

Insulin resistance seems to be one of the factors involved in T2D which is caused, by low-grade chronic inflammation13-15 among other factors. Interestingly, low-grade chronic inflammation is a hallmark16-19 in T2D patients.

Considering these factors, it seems plausible that the nutrition introduced with the agricultural revolution 10,000 years ago played an important role in the current diabetes epidemic in Westernized populations. Western foods are overload with antinutrients, namely lectins, saponins and gliadin, which may explain the great disparity between paleolithic and modern Western food when it comes to metabolic syndrome (a combination of medical disorders that increase the risk of developing cardiovascular disease and diabetes). There is evidence showing that antinutrients act as endocrine disrupting substances, promoting metabolic syndrome20. On the other hand, antinutrients may elicit their negative health effects through increased intestinal permeability21. However, scant evidence exists regarding the role of antinutrients in the aetiology of Western diseases.

Gliadin and increased intestinal permeability

One of the most studied foods in the recent years is wheat, which contains a protein called gliadin, and is part of the gluten protein family22. Gliadin increases gut permeability by means of Zonulin production (a protein that regulates in tight junctions between cells in the wall of the digestive tract) in the gut enterocytes (epithelial cells found in the small intestines and colon). Zonulin binds the CXCR3 chemokine receptor leading to intracellular signalling cascades, mediated by protein kinase C (PKC), which ultimately causes disruption of the tight junction proteins which maintain the gut barrier function, and lead to increased gut permeability23, 24.

In addition, when intestinal permeability is increased, gliadin - which is resistant to heat and digestive enzymes - is able to interact with gut associated lymphoid tissue (GALT) stimulating the innate immune system, leading to low-grade chronic inflammation22, 24. Several studies have demonstrated that gliadin induces the production of pro-inflammatory cytokines (a small protein released by cells that has a specific effect on the interactions between cells, communications between cells or the behavior of cells), independent of one’s genetic predisposition to celiac disease – which is virtually everyone23, 25, 26.

Lectins and increased gut permeability

Lectins are a family of glycoproteins (a complex protein containing a carbohydrate combined with a simple protein) found in the plant kingdom, including grains, legumes and solanacous plants (tomatoes, potatoes, eggplants and peppers)21, 27. Lectins also have the ability to bind sugar containing molecules. They were first studied for their ability to agglutinate (cause to adhere) red blood cells by binding to their cell membranes. Many lectins present in other foods are harmless, but some lectins found in grains, legumes and solanaceous plants have been shown to be harmful to human physiology28. Lectins are resistant to heat (unless cooked by pressure cooking)29 and digestive enzymes38, and therefore arrive intact when they reach the intestinal epithelium, passing through the intestinal barrier into peripheral circulation. Lectins are able to bind peripheral tissues, producing many deleterious health effects21. Furthermore, lectins disrupt intestinal barrier and immunological function when they bind surface glycans (a carbohydrate polymer containing simple sugars) on gut epithelial cells, causing cellular disruption and increasing gut permeability. Lectins also facilitate the growth of certain bacteria strains, stimulate T-cell proliferation, increase intercellular adhesion molecules (ICAM), stimulate production of pro-inflammatory cytokines (IL-1, TNF-alpha, etc.), and amplify HLA class II molecules expression, among other effects21.

Saponins and increased gut permeability

Saponins are glycoalkaloids (a family of poisons commonly found in the plant species Solanum dulcamara - nightshades) produced by plants, technically known as steroid glycosides or triterpenoids, are formed by a sugar compound (glucuronic acid, glucose or galactose, among others) and aglycone (non-sugar molecule) portion30-32. The aglycone portion binds the cholesterol molecule on gut cell membranes. When certain amounts of saponins bind cell membrane cholesterol molecules of the intestinal epithelial cells at a 1:1 ratio, the sugar portion of the saponins bind together, resulting in a complex molecule consisting of cholesterol and saponins. This new molecule disrupts the gut barrier and increases intestinal permeability. This has been shown in humans who consume a diet rich in alpha-solanine and alpha-chaconine - two of the saponins found in potatoes31.

On the other hand, saponins have adjuvant-like activity, which means that they are able to affect the immune system leading to pro-inflammatory cytokine production33, 34, ultimately inducing insulin resistance.

Intestinal permeability and endotoxemia

Intestinal epithelia act as a physical barrier between the outside and the inside of the body, meaning that the intestinal lumen is technically outside the organism. When the intestinal barrier is disrupted, it allows increased passage of gut luminal antigens derived from food, bacteria and viruses into the organism21. In case of bacteria derived antigens, lipopolysaccharide (LPS) is the most commonly studied and utilized antigen to induce acute immune stimulation, this is known as endotoxemia (the presence of endotoxins - a toxin that forms an integral part of the cell wall of certain bacteria - in the blood which may cause hemorrhages, necrosis of the kidneys, and shock)35. In addition, endotoxemia is associated with low-grade chronic inflammation, insulin resistance and T2D13, 18, 36. In a recent human study it was demonstrated that LPS induced low-grade chronic inflammation in adipose tissue in T2D36 humans.

LPS-TLR4 interaction and low-grade chronic inflammation

The innate immune system is localised in the GALT. When luminal antigens pass through the intestinal barrier, they are phagocited (consumed) by dendritic cells or macrophagues, key components of the innate immune system. Dendritic cells or macrophagues recognize antigens through a family of receptors known as Toll-like receptors (TLR). The best studied and known antigens from gram negative bacteria are LPS which interact with toll-like receptors-4 (TLR4), inducing the production of pro-inflammatory cytokines and ultimately insulin resistance and T2D35. Interestingly, a recently published study demonstrated increased TLR4 expression in T2D humans, contributing to an increased inflammatory state37.

In summary, antinutrients introduced with the agricultural revolution 10,000 years ago may be one of the causal factors in the epidemic of obesity, (as well as T2D) in Western countries. Lectins, saponins and gliadin increase intestinal permeability and allow increased passage of gut bacteria from intestinal lumen to peripheral circulation. LPS - an antigen found in gram-negative bacteria cell membranes - interacts with TLR-4, leading to inflammatory cytokine production and low-grade chronic inflammation, which is at the root of insulin resistance. Insulin resistance is recognised to induce the metabolic syndrome, including T2D. Endotoxemia-induced insulin resistance in T2D patients may be exacerbated, in part, by antinutrients.

References:
Stumvoll M, Goldstein BJ, van Haeften TW. Type 2 diabetes: principles of pathogenesis and therapy. Lancet 2005;365(9467):1333-46.Joffe BI, Jackson WP, Thomas ME, Toyer MG, Keller P, Pimstone BL. Metabolic responses to oral glucose in the Kalahari Bushmen. British medical journal 1971;4(5781):206-8.Lindeberg S, Eliasson M, Lindahl B, Ahren B. Low serum insulin in traditional Pacific Islanders--the Kitava Study. Metabolism: clinical and experimental 1999;48(10):1216-9.Merimee TJ, Rimoin DL, Cavalli-Sforza LL. Metabolic studies in the African pygmy. The Journal of clinical investigation 1972;51(2):395-401.Spielman RS, Fajans SS, Neel JV, Pek S, Floyd JC, Oliver WJ. Glucose tolerance in two unacculturated Indian tribes of Brazil. Diabetologia 1982;23(2):90-3.Zimmet P. Epidemiology of diabetes and its macrovascular manifestations in Pacific populations: the medical effects of social progress. Diabetes care 1979;2(2):144-53.Cruickshank JK, Mbanya JC, Wilks R, Balkau B, McFarlane-Anderson N, Forrester T. Sick genes, sick individuals or sick populations with chronic disease? The emergence of diabetes and high blood pressure in African-origin populations. International journal of epidemiology 2001;30(1):111-7.O'Dea K. Marked improvement in carbohydrate and lipid metabolism in diabetic Australian aborigines after temporary reversion to traditional lifestyle. Diabetes 1984;33(6):596-603.O'Dea K, Spargo RM, Akerman K. The effect of transition from traditional to urban life-style on the insulin secretory response in Australian Aborigines. Diabetes care 1980;3(1):31-7.O'Dea K, Spargo RM, Nestel PJ. Impact of Westernization on carbohydrate and lipid metabolism in Australian Aborigines. Diabetologia 1982;22(3):148-53.Jonsson T, Granfeldt Y, Ahren B, et al. Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovascular diabetology 2009;8:35.Lindeberg S, Jonsson T, Granfeldt Y, et al. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia 2007;50(9):1795-807.Fernandez-Real JM, Pickup JC. Innate immunity, insulin resistance and type 2 diabetes. Trends in endocrinology and metabolism: TEM 2008;19(1):10-6.Reyna SM, Ghosh S, Tantiwong P, et al. Elevated toll-like receptor 4 expression and signaling in muscle from insulin-resistant subjects. Diabetes 2008;57(10):2595-602.Song MJ, Kim KH, Yoon JM, Kim JB. Activation of Toll-like receptor 4 is associated with insulin resistance in adipocytes. Biochemical and biophysical research communications 2006;346(3):739-45.Duncan BB, Schmidt MI. The epidemiology of low-grade chronic systemic inflammation and type 2 diabetes. Diabetes technology & therapeutics 2006;8(1):7-17.Kimberly MM, Cooper GR, Myers GL. An overview of inflammatory markers in type 2 diabetes from the perspective of the clinical chemist. Diabetes technology & therapeutics 2006;8(1):37-44.Pickup JC. Inflammation and activated innate immunity in the pathogenesis of type 2 diabetes. Diabetes care 2004;27(3):813-23.Spranger J, Kroke A, Mohlig M, et al. Inflammatory cytokines and the risk to develop type 2 diabetes: results of the prospective population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study. Diabetes 2003;52(3):812-7.Jonsson T, Olsson S, Ahren B, Bog-Hansen TC, Dole A, Lindeberg S. Agrarian diet and diseases of affluence--do evolutionary novel dietary lectins cause leptin resistance? BMC endocrine disorders 2005;5:10.Cordain L, Toohey L, Smith MJ, Hickey MS. Modulation of immune function by dietary lectins in rheumatoid arthritis. The British journal of nutrition 2000;83(3):207-17.Fasano A. Surprises from celiac disease. Scientific American 2009;301(2):54-61.Drago S, El Asmar R, Di Pierro M, et al. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scandinavian journal of gastroenterology 2006;41(4):408-19.Visser J, Rozing J, Sapone A, Lammers K, Fasano A. Tight junctions, intestinal permeability, and autoimmunity: celiac disease and type 1 diabetes paradigms. Annals of the New York Academy of Sciences 2009;1165:195-205.Bernardo D, Garrote JA, Fernandez-Salazar L, Riestra S, Arranz E. Is gliadin really safe for non-coeliac individuals? Production of interleukin 15 in biopsy culture from non-coeliac individuals challenged with gliadin peptides. Gut 2007;56(6):889-90.Rakhimova M, Esslinger B, Schulze-Krebs A, Hahn EG, Schuppan D, Dieterich W. In vitro differentiation of human monocytes into dendritic cells by peptic-tryptic digest of gliadin is independent of genetic predisposition and the presence of celiac disease. Journal of clinical immunology 2009;29(1):29-37.Kilpatrick DC, Pusztai A, Grant G, Graham C, Ewen SW. Tomato lectin resists digestion in the mammalian alimentary canal and binds to intestinal villi without deleterious effects. FEBS letters 1985;185(2):299-305.Cordain L. Cereal grains: humanity's double-edged sword. World review of nutrition and dietetics 1999;84:19-73.Grant G, More LJ, McKenzie NH, Pusztai A. The effect of heating on the haemagglutinating activity and nutritional properties of bean (Phaseolus vulgaris) seeds. Journal of the science of food and agriculture 1982;33(12):1324-6.Francis G, Kerem Z, Makkar HP, Becker K. The biological action of saponins in animal systems: a review. The British journal of nutrition 2002;88(6):587-605.Patel B, Schutte R, Sporns P, Doyle J, Jewel L, Fedorak RN. Potato glycoalkaloids adversely affect intestinal permeability and aggravate inflammatory bowel disease. Inflammatory bowel diseases 2002;8(5):340-6.Keukens EA, de Vrije T, van den Boom C, et al. Molecular basis of glycoalkaloid induced membrane disruption. Biochimica et biophysica acta 1995;1240(2):216-28.Oda K, Matsuda H, Murakami T, Katayama S, Ohgitani T, Yoshikawa M. Adjuvant and haemolytic activities of 47 saponins derived from medicinal and food plants. Biological chemistry 2000;381(1):67-74.Pickering RJ, Smith SD, Strugnell RA, Wesselingh SL, Webster DE. Crude saponins improve the immune response to an oral plant-made measles vaccine. Vaccine 2006;24(2):144-50.Cani PD, Bibiloni R, Knauf C, et al. Changes in gut microbiota control metabolic endotoxemia-induced inflammation in high-fat diet-induced obesity and diabetes in mice. Diabetes 2008;57(6):1470-81.Creely SJ, McTernan PG, Kusminski CM, et al. Lipopolysaccharide activates an innate immune system response in human adipose tissue in obesity and type 2 diabetes. American journal of physiology 2007;292(3):E740-7.Dasu MR, Devaraj S, Park S, Jialal I. Increased toll-like receptor (TLR) activation and TLR ligands in recently diagnosed type 2 diabetic subjects. Diabetes care;33(4):861-8.Pusztai A and Grant G. Assessment of lectin inactivation by heat and digestion. From Methods in Molecular Medicine. Vol 9 Lectin methods and protocols. Edited by J M Rhodes and J D Milton Humana Press Inc. Totowa, NJ.

The Paleo Diet and Crohn's Disease

Q: Can you comment on any reported results in curbing the symptoms of Crohn's Disease with the Paleo Diet. As I am a sufferer, I would love to know.

Thank you,
Shannon

A: Dear Shannon,

Indeed, inflammatory bowel disease (Ulcerative Colitis & Crohn's Disease) patients usually do very well with The Paleo Diet, as nutrients are one of the main environmental triggers of this condition. Crohn's disease is an autoimmune disease where the immune system mounts an attack against its own tissues - in this case the cells lining the intestine.

For an autoimmune disease to occur we need a genetic predisposition and an environmental trigger. The genetic predisposition depends on genes coding for the Human Leukocyte Antigen (HLA) system. One of the environmental triggers may be nutrition, besides infections, geography (vitamin D deficiency), physical trauma or vaccination.

One of the key points in this process is increased intestinal permeability. This means that the gut barrier allows increased passage of bacterial or food proteins (antigens) into peripheral circulation, skipping a process known as oral tolerance. Once antigens come in contact with the immune system located in the gut associated lymphoid tissue, they may elicit a T-cell mediated immune response against those antigens.

If the molecular structure of the dietary or bacterial antigens is similar to that of the HLA system (part of the immune system representing cellular mechanisms), chances are that a cross reaction between foreign antigens and self antigens (produced by T-cells) occur. This is termed molecular mimicry, and leads to self injury by the adaptive immune system.

Hence, decreasing intestinal permeability is one of the treatment targets. There are several nutrients known to increase intestinal permeability that you may want to avoid, at least until symptoms subside. Here is a list, with the noxious substances in parentheses:

Cereal grains (lectins and gliadin)Legumes, including soya and peanuts (lectins and saponins)Tomato (tomato lectin and alpha-tomatin)Potato (lectins and saponins)Chili (capsaicin)Quillaja (foaming substance)Quinoa (saponins)Egg white (lysozyme)Alfalfa sprouts (saponins)Amaranth (saponins)Alcohol

Moreover, some nutrients exert an adjuvant-like activity (they stimulate the immune system), which is something you don't want to if you are suffering from an autoimmune disease. Nutrients containing adjuvants:

Quillaja extract, found in root beerTomato alpha-tomatine

Dairy products and vegetable oils also have deleterious effects upon your immune system.

I hope this helps.
Maelán

Chia Seeds Follow-up

Dear Readers,

This Q & A is in response to Dr. Cordain's special report on Chia Seeds, which appeared in a recent issue of our newsletter, The Paleo Diet Update. The full report is available in The Paleo Diet Update, Volume 6 Issue 7.

Q: Loren,

Hope all is well with you and your work!

After reading your article on chia seeds, I forwarded the article to Dr. Vlad Vuksan in Canada, one of the leading researchers/promoters of Salba Seeds. After he got your article, he seemed to object that your conclusions apply uniquely to chia seeds generically, but not to Salba Seeds (single variety).

Is such a distinction valid? Wouldn't your conclusions regarding chia seeds apply as well to Salba, a variety of chia?

Thanks for your insights,
Frank

A: Hi Frank,

I stand by my conclusions in the newsletter. Until further human trials are completed employing a sample size with sufficient statistical power to resolve these immune system issues, then the potential adverse effects of long term, chronic chia seed consumption may outweigh the potential benefits. I respect Dr. Vukan’s long time collaborative work with David Jenkins at the University of Toronto, particularly in regard to their pioneering work on the glycemic index. I have read both of Dr. Vukan’s recent chia seed papers1, 2, and in neither one do the authors make any distinction between generic Salvia hispanica L. and the trade name (Salba) version of the seed they employed in their two studies. Hence, unless Dr. Vukan and colleagues can show otherwise, the literature results I have uncovered remain unchanged and apply to both Salba and Salvia hispanica L. It should be noted that at least two of the subjects in Dr. Vukan’s first study2 refused to continue because of gastrointestinal side effects.

In regard to Dr. Vukan’s first chia study, Table 1 shows a non-significant decrease (7.0 %) in the treatment group’s CRP and a 32.9 % increase in the control group value. The authors interpret this bi-directional group change in the abstract and elsewhere as a significant reduction (40 + 1.6% p less than 0.04) in CRP. This kind of data reporting is misleading when the treatment group mean change was actually non-significant. Despite ANCOVA adjustment for age, gender and sequence in their repeated measures model, their interpretation of the CRP data is at best misleading but likely incorrect. An additional shortcoming in this study involves the reporting of ALA and EPA data (results p. 2806). Why weren’t the actual plasma concentrations (mean + SD) of both of these fatty acids reported in both the experimental and control group? Given that 2% or less of ALA is chain elongated and desaturated into DHA, the EPA data need further scrutiny. Did the reported % differences for ALA and EPA represent within group differences or factorial differences? These shortcomings potentially invalidate the conclusions of the paper that CRP was reduced. In contrast, Nieman and colleagues3 were unable to replicate Dr. Vukan and colleague’s results in a similar study with a much larger sample size and hence greater statistical power.

Cordially,
Loren Cordain, Ph.D., Professor

References:
Vuksan V, Jenkins AL, Dias AG, Lee AS, Jovanovski E, Rogovik AL, Hanna A. Reduction in postprandial glucose excursion and prolongation of satiety: possible explanation of the long-term effects of whole grain Salba (Salvia Hispanica L.). Eur J Clin Nutr. 2010 Apr;64(4):436-8.
Vuksan V, Whitham D, Sievenpiper JL, Jenkins AL, Rogovik AL, Bazinet RP, Vidgen E, Hanna A. Supplementation of conventional therapy with the novel grain Salba (Salvia hispanica L.) improves major and emerging cardiovascular risk factors in type 2 diabetes: results of a randomized controlled trial. Diabetes Care. 2007 Nov;30(11):2804-10
Nieman, D., C., E. J. Cayea, M. D. Austin, D. A. Henson, S. R. McAnulty, F. Jin. 2009. Chia seed does not promote weight loss or alter disease risk factors in overweight adults. Nutrition Research, 29(2009):414-418.

Paleo Links

Dear Readers,

In addition to our paleo nutrition links on the right-hand side of the blog (scroll down if not visible), here are useful links for fitness, Paleo Diet, and paleo nutrition-related web sites and blogs.

Radio Interview with Dr. Cordain

Dear Readers,

Dr. Cordain was a guest on the The Soul's Edge radio program on KKNW Alternative Talk Radio, 1150 AM, in Seattle on March 30. You may listen to an MP3 recording of the interview from our web site. The segment with Dr. Cordain begins at time index 15:23 in the MP3 recording.

Consumption of Nightshade Plants (Parts 1 -3) Newsletter Articles

Dear Readers,

The three most recent editions of our weekly newsletter The Paleo Diet Update (Vol. 6 Issues 15-17) featured Dr. Cordain's newest paper "Consumption of Nightshade Plants". The final installment (three of three) was published last week. All three parts of the newsletter will available for purchase as back issues from our web store until July 5, after which the entire paper will be available from our web store.

Thank you for your continued readership.

Paleo Diet Q & A - Lichen Sclerosis, Stevia

Lichen Sclerosis

Q: Hi there - I have been following a Paleo Diet for a few weeks now and there is no doubt that I feel much better for it. I did not need to lose weight and I always regarded myself as pretty fit and healthy. However, a little while back I developed a troublesome skin condition called Lichen Sclerosis. Have you ever been asked about this condition and suggested dietary changes? I think part of the problem is that the etiology is not fully understood but many doctors seem to think it has an autoimmune component though I have read recent research that suggests oxidative damage plays a part and that antioxidant therapy may be useful in treatment. This condition is supposedly incurable (though manageable with potent steroids) but I'm sure it would give a great many people some comfort if simple dietary changes could help. Would be really great to hear your thoughts.

Simon

A: Dear Simon,

The available evidence indicates that an autoimmune component likely occurs with Lichen Sclerosis (LS). With all autoimmune diseases, an autoantigen (self protein) exists and represents the target protein being attacked by the immune system. About 75 % of LS patients maintain an IgG autoantibody to Extra Cellular Matrix Protein 1 (ECM1)1. Acceleration of ECM1 deposition in dermal (skin) blood vessels may underlie the disease symptoms 2, 3. So the question now arises, what causes an accelerated deposition of ECMI in dermal blood vessels in LS patients? The available evidence indicates that increased concentrations of a ubiquitous enzyme in the body called tissue transglutaminase (TG2) is primarily responsible for excessive ECM1 accumulation3. In medical terms, an increase in a concentration of a substance in the bloodstream by another substance is called "upregulation".

So, in LS patients, an upregulation of TG2 causes an upregulation and increased deposition of ECMI in the skin blood vessels in the affected area of the body. The next question to be posed is, what event or events trigger an upregulation of TG2? When we answer this question, then dietary recommendations advocated by the Paleo Diet will make sense. A storage protein called gliadin which is fournd in wheat, rye, barley and oats is known to upregulate TG2 4-7. Hence grain free diets may prove to be therapeutic for LS patients, although no current randomized controlled trials of this intervention strategy have yet been conducted.

Cordially,
Loren Cordain, Ph.D., Professor

References:

Chan I, Oyama N, Neill SM, Wojnarowska F, Black MM, McGrath JA. Characterization of IgG autoantibodies to extracellular matrix protein 1 in lichen sclerosus. Clin Exp Dermatol. 2004 Sep;29(5):499-504. Kowalewski C, Kozlowska A, Chan I, Górska M, Wozniak K, Jablonska S, McGrath JA.Three-dimensional imaging reveals major changes in skin microvasculature in lipoid proteinosis and lichen sclerosus. J Dermatol Sci. 2005 Jun;38(3):215-24. Epub 2005 Mar 3. Fisher M, Jones RA, Huang L, Haylor JL, El Nahas M, Griffin M, Johnson TS. Modulation of tissue transglutaminase in tubular epithelial cells alters extracellular matrix levels: a potential mechanism of tissue scarring. Matrix Biol. 2009 Jan;28(1):20-31. Epub 2008 Nov 5. Michaelsson, G., Ahs, S., Hammarstrom, I., Lundin, I. P., & Hagforsen, E. Gluten-free diet in psoriasis patients with antibodies to gliadin results in decreased expression of tissue transglutaminase and fewer ki67+ cells in the dermis. Acta Dermato-Venereologica, 2003; 83(6):425-429. Biagi F, Campanella J, Laforenza U, Gastaldi G, Tritto S, Grazioli M, Villanacci V, Corazza GR. Transglutaminase 2 in the enterocytes is celiac specific and gluten dependent. Dig Liver Dis. 2006 Sep;38(9):652-8. Gorgun J, Portyanko A, Marakhouski Y, Cherstvoy E. Tissue transglutaminase expression in celiac mucosa: an immunohistochemical study. Virchows Arch. 2009 Oct;455(4):363-73. Villanacci V, Not T, Sblattero D, Gaiotto T, Chirdo F, Galletti A, Bassotti G. Mucosal tissue transglutaminase expression in celiac disease. J Cell Mol Med. 2009 Feb;13(2):334-40.

Stevia

Q: Is Stevia Paleo? I have attempted to find an answer for this and the information I've found is conflicting at best. Please advise!!
Jeff

A: Dear Jeff,

There's some scientific evidence to support the notion that Stevia is safe, even in type 2 diabetes patients1, 2. Furthermore, it has been demonstrated to have antihypertensive properties, as shown by Chan et al.3 and a long-term study4. Having said this, I am not aware of any study examining the potential antinutrient (lectins or saponins) content of the plant, hence we do not know the possible adverse effect of consuming this plant on a daily basis. Hunterh-gatherers used to consume a wide range of plants, thereby minimizing the amount of a single bioactive compound ingested and its toxicity. It is known that rotating the kind of plants is a good strategy in order to decrease food allergy and intolerance.

From an evolutionary standpoint we should look at nutrition as "whole food" rather than nutrients per se. The bottom line is that Stevia seems to be safe, but we need more research to rule out possible side effects.

I hope this is helpful,
Maelán

References

Gregersen S, Jeppesen PB, Holst JJ, Hermansen K. Antihyperglycemic effects of stevioside in type 2 diabetic subjects. Metabolism. 2004 Jan;53(1):73-6. Barriocanal LA, Palacios M, Benitez G, Benitez S, Jimenez JT, Jimenez N, Rojas V. Apparent lack of pharmacological effect of steviol glycosides used as sweeteners in humans. A pilot study of repeated exposures in some normotensive and hypotensive individuals and in Type 1 and Type 2 diabetics. Regul Toxicol Pharmacol. 2008 Jun;51(1):37-41. Epub 2008 Mar 5. Chan P, Tomlinson B, Chen YJ, Liu JC, Hsieh MH, Cheng JT. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol. 2000 Sep;50(3):215-20. Hsieh MH, Chan P, Sue YM, Liu JC, Liang TH, Huang TY, Tomlinson B, Chow MS, Kao PF, Chen YJ. Clin Ther. 2003 Nov;25(11):2797-808. Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study.

Sample Menus for Endurance Athletes

Dear Readers,

Nell Stephenson, Fitness & Nutritional Professional, Ironman Triathlete, and contributor to our newsletter was recently contacted by Details magazine to write up sample menus for endurance athletes: one for a workout day, the other for an off-day from training.

You will find other paleo-friendly menu ideas on Nell's blog.

Endurance Athlete Sample Menu for Two-a-Day Workout

5:30 AM
Pre-workout Breakfast Smoothie- 8oz brewed, chilled, natural decaf green tea with a banana, egg white protein powder, almond butter whizzed in the blender with some baked yam on the side.

6:30 AM
3-hour bike ride on the trainer-carbohydrate gel taken every 25 minutes.

9:30 AM
Immediate Post-workout recovery drink- HOME BREW (recipe in The Paleo Diet for Athletes) – cantaloupe, egg white protein powder and glucose. Drink plenty of water- keep hydrating.

10:00 AM
Raisins (to restore body alkalinity, continue to help the body recover post workout, and prepare for the session later in the day).

11:30 or 12:00 PM
Grilled Chicken breast, flash-sautéed asparagus, drizzled with flax seed oil and an apple

3:00 PM
Natural unsweetened applesauce with chopped egg whites (to prepare for 2nd workout of the day-shift from the usual Paleolithic macronutrient ratio to the pre-workout focus on carbohydrates).

4:30 PM
Sixty-minute track workout-hard, fast intervals; carbohydrate gel taken immediately post as recovery.

5:45 PM
Banana (high glycemic fruit choice to, again, aid in recovery)

6:30 PM
Poached wild salmon on a bed of steamed kale, mixed green salad, avocado & sliced strawberries, a squeeze of fresh lime juice and a splash of cold-pressed extra virgin oil; sliced oranges on top.

Endurance Athlete Sample Menu for Off-Day from Training

6:00 AM Breakfast
Poached Cod (or Barramundi) on bed of sautéed spinach (with garlic & olive oil), fresh blueberries and strawberries.

9:00 AM
Steamed broccoli, drizzled with cold pressed flax seed oil, sliced orange and chopped egg whites.

Lunch
Mixed green organic salad, with olive oil and lime wedge, served with grilled chicken, avocado and grapes.

Afternoon Meal
Sliced lean turkey breast used as a wrap, with Mache lettuce, raw almond butter and sliced pear inside.

Dinner
Kangaroo Kebabs-lean meat, skewered with red onion & yellow bell peppers, marinated over night in olive oil, lemon juice & your favorite herbs, then grilled or broiled. Serve with grilled green onion and a fresh spinach salad with tomato, walnut oil & a lime wedge.

Snack
Cinnamon dusted sliced apples-slice an apple, toss in lemon juice to prevent browning/oxidation, then sprinkle cinnamon on top. Enjoy with a cup of herbal or green decaf tea!

Fundraiser for Documentary Series: In Search of the Perfect Human Diet™

Fund raising continues for The Ancestral Health Society & Foundation's post-production work on the international documentary series In Search of the Perfect Human Diet™. The four-part series features the world’s leading scientists and advocates in human evolutionary nutrition. For the first time a major television & DVD release will document proof of the Paleo Diet principles.

Donations of $100 or more will get a Special Edition DVD set and Film Credit for their support.

Distribution of this series will create important ongoing financial support for the Ancestral Health Society's non-profit foundation and educational mission via direct financial contributions from all DVD sales.

The four-part series features the world’s leading scientists and advocates in human evolutionary nutrition, including:
Dr. Loren Cordain (author of The Paleo Diet, Colorado State University)Dr. Michael Richards (Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany -Department of Human Evolution)Dr. Jay Wortman (Inuit Diet research, Canada)Dr. Steve Phinney (Professor Emeritus of Medicine, UC Davis)Gary Taubes (New York Times science writer and author of Good Calories, Bad Calories)Dr. Michael R. Eades (author of Protein Power)Barry Sears Ph.D. (author of The Zone)Dr. Leslie C. Aiello (President, Wenner-Gren Foundation for Anthropological Research, New York)Robb Wolf (Research bio-chemist, author of The Paleolithic Solution)Professor Richard D. Feinman, PhD (Downstate Medical Center (SUNY) in New York)Professor Craig Stanford (Chair, Department of Anthropology, USC)Dr. Lane Sebring (Sebring Clinic, Wimberley, TX)Eric Schlosser (author of Fast Food Nation)And many more…This fundraiser will enable Hunt Thompson Media, LLC to finish the international documentary series post-production work by Thanksgiving 2010, and release it for the 2010 Christmas and the 2011 New Year's resolution season. For more information on the documentary series visit www.perfecthumandiet.com.

To make a donation click the Chip In button below.

Announcing: The Paleo Diet Cookbook

Editor's note: Dr. Cordain's latest publishing projects include The Paleo Diet Cookbook, available for purchase on December 13, 2010. This article includes a brief interview with Dr. Cordain.

Patrick Baker (PB): What did you hope to achieve by publishing your own cookbook?

Dr. Loren Cordain (LC): The Paleo Diet Cookbook will be published by John Wiley & Sons, the publisher of my first book, The Paleo Diet. Because of the enormous success of The Paleo Diet, my publisher wanted us (me, my wife Lorrie Cordain, and Nell Stephenson) to write a follow-up cookbook that would provide my readers with a "how to, hands on" easy approach to preparing and making delicious Paleo meals and snacks. The book contains more than 150 recipes arranged into the following chapters and topics:
IntroductionCHAPTER 1: The Paleo Diet BasicsCHAPTER 2: Paleo Kitchen BasicsCHAPTER 3: Paleo Breakfasts DishesCHAPTER 4: Paleo Snacks and AppetizersCHAPTER 5: Paleo PoultryCHAPTER 6: Paleo Beef, Pork, and LambCHAPTER 7: Grass- Fed Meat, Game Meat and JerkyCHAPTER 8: Paleo Fish and SeafoodCHAPTER 9: Paleo SaladsCHAPTER 10: Paleo Vegetable DishesCHAPTER 11: Condiments, Salad Dressings, Sauces and Fruit PureesCHAPTER 12: Paleo Beverages and DessertsCHAPTER 13: The Paleo Diet Two Week Meal PlanCHAPTER 14: Treats and Meals for Crossfitters and AthletesPB: Given the proliferation of other paleo cookbooks, what makes yours stand out?

LC: I am aware of two other cookbooks that have taken the Paleo approach, however it turns out that many of the recipes are not pure Paleo, and use salt, honey and other non-Paleo ingredients. This book comes straight from the originator of The Paleo Diet, and I can assure my readers that all of the recipes in the book are not only pure Paleo, but also appetizing and nutritious. Nell and Lorrie have done a wonderful job creating some brand new incredibly delicious recipes and snacks.

PB: In general, how does the cookbook reflect the principles outlined in your book The Paleo Diet?

LC: In the first chapter of the book, I outline the basics of Paleo dieting - all the do's and dont's that experienced Paleo Dieters may be aware of, but also great background material for newbies to Paleo Dieting. Actually, as most of our veteran readers realize, The Paleo Diet is not a diet at all, but rather a lifetime plan of eating to optimize health and well being. I've also devoted a large section of Chapter I to autoimmune diseases, and how Paleo Diets can ameliorate symptoms of these illnesses. This is brand new information which has never been published.

PB: Do you cross-reference any of your other published work in the cookbook?

LC: The Paleo Diet Cookbook is consistent with most of the work from my prior three books. However, I have completely updated it based upon the most recent scientific evidence. A couple of key points are different from my first book, The Paleo Diet, which was published in 2002. First, I no longer advocate the use of canola oil, for reasons explained in the book, and I have also taken a softer stand on saturated fats based upon my own article on the topic, published in 2006, and available as a free PDF download from my website. Further, I now advocate coconut and coconut oil consumption.

PB: When will your cookbook be available for purchase?

LC: The Paleo Diet Cookbook can be pre-ordered right now at Amazon, but it will not ship until December 13, 2010.

PB: Where can your readers purchase a copy of your cookbook when it becomes available?

LC: The Paleo Diet Cookbook, as well as my upcoming 2010 Revision to The Paleo Diet, can be purchased at my website, at Amazon, or almost any local bookstore.

Paleo Diet Q & A - Saturated Fat

Dear Readers,

This question has come up several times in recent weeks. Maelán's response warrants breaking this out from among the other questions answered in the original post. Included in this post is a link to Dr. Cordain's paper on the subject.

Q: I wanted to ask you why it is that you discourage saturated fats in the paleo diet? From what I have read their are healthy saturated fats from coconuts that are used for around 17% of the Kitavan diet. Also, what about tubers such as sweet potato and yam, do you think that consuming these in moderate portions (small enough to keep a low glycemic load) could be detrimental?

A: Regarding saturated fats:

Saturated fatty acids intake and the risk of developing cardiovascular disease (CVD) is a topic with a lot of controversy. In recent years a wide body of research has suggested that increased consumption of certain saturated fatty acids (Lauric acid, myristic acid and palmitic acid)
down-regulate LDL receptor and thereby increase LDL plasma levels, and this has been associated to increased risk of CVD. On the other hand, stearic acid (a 18 carbon saturated fatty acid) has been shown to decrease LDL plasma levels. However, this view is too simplistic as they are several other factors contributing to CVD, such as smoking, exercise, trans-fatty acids, increased omega-6/omega-3 ratio, free-radicals, nutrient deficiency, homocysteine, alcohol intake and low-grade chronic inflammation among others.

Moreover, some studies have suggested that there’s not enough scientific data to support the view that increased total or LDL cholesterol is an independent risk factor for CVD, but rather oxidized LDL. Plaque production is mediated by oxidized LDL but not LDL. Oxidized LDL can produce shedding of the inner layer of the artery namely glycocalix. Then oxidized LDL infiltrates in the intima of the artery. Oxidized LDL is eaten by macrophagues, a process known as phagocytosis, and therefore macrophagues are transformed into foam cells which produce the fibrous cap.

Once the fibrous cap has been produced we need to break it down in order to produce an ischemic event. Lectins and low-grade chronic inflammation are involved in the activation of matrix metalloproteinases which break down the fibrous cap.

In summary, high total cholesterol or LDL levels do not increase CVD risk but rather oxidized LDL. To produce oxidized LDL we need the factors mentioned above. Hence, consumption of saturated fatty acids is not an issue if we control several other factors such as those mentioned before.

Dr. Cordain wrote a book chapter where he shows that saturated fat consumption in ancient hunter-gatherer populations were usually above recommended 10% (American Heart Association) of energy from saturated fats yet non atherogenic.

The bottom line is that we do not recommend cutting down saturated fatty acid intake but rather decrease high-glycemic load foods, vegetable oils, refined sugars, grains, legumes and dairy.

I hope this helps.
Maelán

Link to supporting paper.