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Kefir Consumption Ill Founded at Best

Kefir Consumption Ill Founded at Best | The Paleo Dit
Hi Dr. Cordain,

Just finished The Paleo Diet for Athletes; I have found it extremely useful so thank you! In the meantime, I noted Chris Kresser has recently been promoting the consumption of Kefir: http://chriskresser.com/kefir-the-not-quite-paleo-superfood

If you are able to comment I would be very interested in your views! I entirely understand if you are unable or unwilling to comment. Suspect you probably get a few emails like this!

Keep up the good work!

Michael

Dr. Cordain’s Response:

Hi Michael,

Good to hear from you and many thanks for your kind words about The Paleo Diet for Athletes.  I note that Chris Kresser has recently become quite a spokesperson for contemporary Paleo Diets, as he recently appeared on the Dr. Oz TV program, espousing the dietary benefits of both dairy products and legumes in contemporary Paleo diets.  A brief check of Chris’s scientific publication record on PubMed for “Paleo Diets,” or any other topic for that matter, comes up with absolutely zilch — zero ! — nothing !  – no publications whatsoever!  This evidence (or lack thereof) lends little credibility to Chris’s claims as an expert in diet, nutrition or anthropology — much less Paleo Diets.  He has simply never put forth his ideas in peer review, scientific journals.  Nevertheless, the presence of scientific publications or advanced degrees don’t always guarantee expert advice; rather good ideas and rationale thought, supported by solid data frequently do.  Chris’s advice that legumes and dairy are indeed “Paleo” foods that should be regularly consumed in contemporary diets mimicking the nutritional characteristics of our pre-agricultural, hunter gatherer ancestors is ill founded at best.

The Paleolithic period or Old Stone Age is generally defined as the time span in which human ancestors first began to manufacture stone tools (about 2.5 million years ago to 3.2 million years ago) until the beginnings of agriculture in the Middle East about 10,000 years.  During this period all humans and our hominid ancestors lived as hunter gatherers and only consumed wild plant and animal foods available in their environments.

Because it is difficult or impossible to milk wild mammals, humans couldn’t have consumed the milk of another species until they were domesticated, beginning about 10,000 years ago.  Even though 10,000 years ago seems to be incredibly distant from a historical perspective; on an evolutionary time scale it only represents about 330 human generations.1 Hence, dairy products (milk, butter, cheese, yogurt, kefir etc.) are very recent introductions into the human diet and never were components of Paleolithic diets.1 In support of this notion is the very recent evolutionary appearance of genes which allow certain human populations on the planet to digest milk without gastro-intestinal upset.2 In fact, about 65 % of the world’s people are lactose intolerant and cannot drink milk without digestive discomfort.  By fermenting dairy products, it is possible to reduce their lactose content, but not all fermented dairy products (yogurt, kumiss, sour milk etc) are completely lactose free.  So the question comes up, should people consuming contemporary Paleo Diets be regularly consuming a food (kefir or for that matter any dairy product) for which our species has scant evolutionary experience? I have fully addressed this issue in an entire chapter in my most recent book, The Paleo Answer.3

It is not the lactose in milk that is the sole reason to avoid dairy.  Except for calcium, milk and dairy products are relative nutritional lightweights in the 13 nutrients most lacking in the U.S. diet.1, 3 Of seven food groups (seafood, meats, fresh vegetables, fresh fruits, milk, whole grains and nuts), milk ranked 5th for the 13 nutrients most deficient in the U.S. diet.  Seafood, meat, fresh vegetables, fresh fruits and nuts provide humans with all known nutritional requirements4 and represent the major food groups that conditioned the human genome for more than 2.5 million years of evolutionary experience.3 No mammal on earth has a nutritional requirement for the milk of another species, nor do we.

Besides its poor nutritional value and indigestibility for 65% of the world’s people, milk and other dairy products may produce a variety of adverse health effects including: 1) a high insulin response and insulin resistance, 2) an increased risk for cardiovascular disease, 3) an increased risk for acne, 4) an increased risk for many autoimmune diseases including multiple sclerosis, rheumatoid arthritis, Crohn’s disease and ulcerative colitis, 5) an increased risk for food allergies,  6) an increased risk for breast, ovarian, prostate and testicular cancers, 7) an increased risk for senile cataracts 8) dairy products’ high calcium content impairs zinc and iron absorption, and finally 9) increased dairy consumption doesn’t reduce the risk for bone fractures – so why consume them?. The mechanisms underlying these adverse health effects are fully outlined in my chapter on the topic, including more than 100 references to support this information.3

If you think milk is just a healthy white liquid that is “Good for Every Body,” think again! The following non-comprehensive list contains hormones and bioactive substances found in cow’s milk which are either known to, or suspected of causing a number of the deleterious health effects associated with milk and dairy consumption.3

Growth Hormones

  • Insulin, Insulin like growth factor 1 (IGF-1), Insulin like growth factor 2 (IGF-2)
  • Insulin like growth factor binding proteins, 1 to 6 (IGFBP-1, 2, 3, 4, 5, 6),
  • Betacellulin (BTC), Growth hormone (GH), Growth hormone releasing factor (GHRF), Transforming growth factor alpha (TGF α), Transforming growth factor beta 1 (TGF-β1), (TGF-β2), Platelet derived growth factor (PDGF)

Steroid Hormones

  • Estrogens (Estrone, Estradiol-17β, Estriol and Estrone sulfate), Progesterone, 20 alpha-dihydropregnenolone, 5α androstanedione, 5 α pregnanedione, 20α- and 20β-dihydroprogesterone, 5α-pregnan-3β-ol-20-one,  5α-androstene-3β17β-diol, 5α-androstan-3β-ol-17-one, androstenedione, testosterone, and DHEA acyl ester

Bioactive Proteins and Peptides

  • Relaxin, Thyrotropin releasing hormone (TRH), Luteinizing hormone releasing hormone (LHRH), Somatostatin (SIH), Gastrin releasing peptide (GRP), Calcitonin, Adrenocorticotropic hormone (ACTH), Prolactin, Thyroid stimulating hormone (TSH), Lysozyme, Lactoperoxidase, Lactoferrin, Transferrin, Immunoglobulins (IgA, IgM, IgG), Proteose-peptone, Glycomacropeptide, Plasmin, α Casein, β Casein, κ Casein, α Lactoglobulin, β Lactoglobulin, Bovine serum albumen (BSA), Gastric inhibitory polypeptide (GIP), Glucagon-like peptide-1 (GLP-1), Antitrypsin, Plasminogen activator inhibitor-1, α(2) antiplasmin , Butyrophilin, Xanthine oxidase, Mucin-1, Mucin-15, Adipohilin, Fatty acid binding protein, CD36, Periodic acid Schiff 6/7

Bioactive Peptides formed in gut from Milk Proteins

  • Casomorphins, α Lactorphin, β Lactorphin, Lactoferroxins, Casoxins, Casokinins, Casoplatelins, Immunopeptides, Phosphopeptides.

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

REFERENCES

1. 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;81:341-54.

2. Cordain, L., Hickey, M. , Kim K. Malaria and rickets represent selective forces for the convergent evolution of adult lactase persistence. In: Biodiversity in Agriculture: Domestication, Evolution and Sustainability, Gepts P, Famula T, Bettinger R et al. (Eds.), Cambridge University Press, Cambridge, UK, 2011, pp 299-308.

3. Cordain L. Just say no to the milk mustache.  In: The Paleo Answer, John Wiley & Sons, New York, NY, 2012, pp. 72-103.

4. Cordain L, The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24.

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14 Comments on "Kefir Consumption Ill Founded at Best"

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  1. I am glad that I opened up this website. I am new to the Paleo diet…I actually do not like the word Diet. For me it is a life style choice.
    I have bin a vegan, vegetarian, but since I moved to Alaska, wild caught salmon, deer, moose, bison is also on my plate, very little I must admit but I enjoy it. I thrive mostly on raw foods, summer 90%, winter 70/80%,
    raw scratch eggs, raw oysters and veggies, sprouts, greens, only organic with some additional cooked meat(only wild, no domestic), raw goat milk kefir and raw cultured vegetables.
    Since I started with the Paleo/low carb choice, my good fat intake has dramatically increased.
    I love it, I have tons of energy and no weight issues. I do sprint8(high interval) 3x a week + high intensity weight training.
    I used to be a total opponent of any dairy but the need for more fat in my diet, made me enjoy raw home made goat milk kefir.
    Thanks for letting me add some comments.

  2. Joseph M says:

    If Chris Kresser doesn’t like to be attacked, he should not attack first, like he did here with Mat Lalonde:

    http://chriskresser.com/rhr-what-science-really-says-about-the-paleo-diet-with-mat-lalonde

    That post was so rude that I immediately stopped following Kresser and Lalonde

  3. Eugenia says:

    I find it a low blow that Dr Cordain has attacked Chris Kresser this way. Just because Kresser is not a researcher doesn’t mean he doesn’t have any knowledge or experience of what he’s talking about. Maybe he hasn’t, but lack of research publications don’t make someone less knowledgeable. That’s not a measure of a medicine man in my opinion. His results are.

    As for kefir, I would advocate for it, until the Second Coming, no matter what Dr Cordain says against milk. Let me be clear here: yes, unfermented casein A1 milk is a problem. But FERMENTED dairy (with very little lactose in it), from casein A2 animals (e.g. goat/sheep), is not a problem for most people.

    I AM lactose intolerant. If I drink milk out of the carton, my tummy hurts for about 20 minutes (mild pain). But if I drink that same milk as kefir (fermented for 24 hours), I have ZERO problems. Nada.

    I should also add here that I was doing low-carb Paleo, and had constipation problems. Then, I decided to add more probiotics to my diet, and home-made goat milk kefir was my choice. Kefir fixed my problem within a week or so.

    The problem I have with Dr Cordain is that he’s so black and white. It’s exactly why he’s not as popular as Wolf or Sisson (or Kresser) in the Paleo community. He’s just too stubborn. He puts everybody on the same sack, while humans are known to have genetic differences that allow some to eat different things with fewer (or more) problems than others.

    Just because the Paleolithic people didn’t eat dairy doesn’t mean it’s toxic to us when fermented, or raw, or from casein A2. I mean, nuts are AS BAD when eaten unsoaked. Modern almond trees didn’t exist until recently either, they were toxic! And yet, why isn’t Cordain complaining about these too? Or broccoli, a species that didn’t exist in the Paleolithic times?

    I will continue my comment on the legume blog post, a topic which again I don’t agree with Dr Cordain.

    My point is: nothing is black and white. I agree that processed food, seed oils, glutenous grains and sugar are problematic. But for rice, legumes and dairy, there are CONDITIONS that can make them acceptable foods for some.

  4. Thanks Dr. Cordain for clearing some things up about the Paleo Diet that people like Chris Kresser have capitalized and made misleading stances on. In my view, his position on Paleo is quite flimsy, incomplete, and unoriginal. I’d like to share my review of his book on Amazon to you:

    So many books have been written on the Paleo Diet in the last few years that writing another book about it really is almost tautological. In Your Personal Paleo Code, Chris Kresser posits that he disagrees with some of the Paleo Diet adherents and progenitors like Loren Cordain and Robb Wolf (though, wisely, he does not name any names) and promises to provide a more nuanced and less stringent approach. Disappointingly, in the end, when one reads carefully his major points in the book and compares them to the major points in books like The Paleo Diet by Loren Cordain and It Starts With Food by Dallas and Melissa Hartwig, one finds that Kresser’s conclusions are quite similar to the two books mentioned.

    Let’s take just one example: Kresser’s stance on dairy. He advocates to consume it only when you know you can tolerate it. Yet in the end, his overall recommendation really is not different from Cordain’s because this author believes that a Paleo dieter can consume non-Paleo foods without significant harm to their health so long as they keep them to a minimum, and this includes dairy. He also explained that once people understand the basic premise of Paleo, they can modify and tailor their Paleo diets according to what makes them thrive. Specifically, under Cordain’s suggestion, Paleo dieters can eat one to three “open” meals per week. In these open meals, Paleo dieters can eat non-Paleo foods as a meal (within reason, i.e., eating donuts only for dinner is a no). If dairy really bothers you, Cordain is confident that you would not want to incorporate it in your diet automatically and permanently. Though one major difference may be the regularity by which Kresser suggests one should consume dairy given that they can “tolerate” it.

    Dallas and Melissa Hartwig has a program in their book that instructs people how to go on a 30-day cleansing diet eliminating industrial, highly processed foods, grains, legumes, and dairy. Then after 30 days, reintroduce each, one by one, to find out if any or all the food items bother you. Again, no relevant difference to Kresser’s.

    Kresser is insistent that his book differs markedly from all other Paleo books and is the more advanced and more “scientific” version of it (we know he keeps up on scientific studies and seems to believe that he’s the most authoritative interpreter of them); but when examined carefully, it’s simply a bold marketing scheme. He tends to misinterpret other experts’ stance on Paleo/non-Paleo foods to a point where one may not detect the fundamental similarities between his ideas and those of others. In the end, his stance is unoriginal and his book reeks of hypercriticism of other experts. In the midst of plenty of literature and blogs about the Paleo Diet, Kresser has to work extra hard to try prove to people that he has new things to say; unfortunately, he does not, and in the process he unfairly criticizes the giants whose shoulders he is standing on.

  5. Bill Vick says:

    Dr. Cordain is one of my Paleo hero’s along with Rob Wolfe and Mark Sisson but not to take exception with all the controversy on Kefir I can only speak for myself and how Kefir (typically Lifeway or Trader Joe’s) has impacted my life. My background is Northern Europe (Germanic) so I’m not really lactose intolerant but I do avoid most milk and milk products. However, I’ve seen the results from consuming Kefir on a regular basis.

    I now drink close to a gallon of Kefir a week and have stopped, totally stopped my GERD or acid reflux. It’s hard to describe but I just have a feeling of well being and I think Kefir has some part in that.

    I’m more Primal than Paleo, avoid wheat but do occasionally have rice and beans and drink wine daily. I’ve been following the diet for a little over two years and it has not only changed but perhaps saved my life which I have documented elsewhere.

    So, not to take exception with this excellent article but as a voice of one Kefir has done demonstrable good for my gut and well being. My results are mine and thank you and Dr. Cordain for the great information.

  6. Dr. Cordain, thank you for taking the time to write an excellent, thorough and scientifically-sound response to Michael’s question.

    I have read and recommended all of your books, listened to all of your podcast interviews and I am always so impressed with your professionalism and ability to convey complex scientific ideas to the general public. Your efforts have been the foundation of the Paleo movement and now millions of people across the world are enjoying better health because of you.

    However, I’m surprised and slightly disappointed at your reaction to Chris Kresser. While he may not have the scientific credentials to stand up to life-long academics such as yourself, he has done an incredible service to the Paleo/Primal community through his online publications and physical practice. Chris’s work is not only incredibly well researched but he is probably the most unbiased and I think rational Paleo author I have come across.

    While some of his recommendations are at odds with your own research and findings I think you are being unfair in your response. He does not recommend dairy for everyone, only those who can tolerate it after reintroducing it into their initial grain-free, dairy-free trial of the Paleo diet. He certainly does not recommend pasteurized, homogenized milk products. Furthermore, while 65% of the world’s population may be lactose intolerant, Chris points out that lactase persistence is quite prevalent in Europeans (stating that up to 98% of Northern Europeans tolerate lactose). I would posit that a great percentage of those following a Paleo diet (of European decent) would in fact tolerate lactose.

    While this is not in any means an argument FOR the consumption of dairy – and you outline the arguments AGAINST dairy very well in your response – I can’t help but think that you are relying too much on your argument that if our ancestors did not consume a certain food and it is therefore “not Paleo” then we should not consume it today. Does this mean that we can never find any new sources of nutrition that we can potentially thrive on?

    Additionally, I have read Chris Kresser’s material extensively and nowhere does he explicitly recommend legumes. His Personal Paleo Code may be less strict than other Paleo Diets but I assure you he isn’t recommending dairy and legumes to most people. He does outline situations in which dairy may be beneficial or detrimental, depending on the individual.

    Let me finish by saying that I have no affiliation to Chris Kresser and have never met him. Yet I think his work is excellent, thoughtful and completely honest… like yours. Furthermore, I have no scientific background either so the point of this comment is only to stand up for Chris Kresser and indeed other people in the community who are doing great things for a great cause, even if you disagree with them or they don’t have any peer-reviewed scientific publications on PubMed.

    Respectfully,

    David Sciola.

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