Jun 03 2013

Gnomic Advice

Published by at 7:15 pm
Under Despised Theories | News and Views | Nincompoopery

I object, your honor! This trial is a travesty. It’s a travesty of a mockery of a sham of a mockery of a travesty of two mockeries of a sham.

— Fielding Melish

Blood Type Diets Don’t Work,” “No Science Behind Blood Type Diets,” scream headlines on mass media sites like Reuters and NewsMax, who report the results of a study published in the latest edition of the American Journal of Clinical Nutrition (AJCN).

Now, you might think that a scientific article that could generate that type of headline actually went ahead and did what is normally done to subject a theory to scientific scrutiny: Test the theory clinically, preferably by some sort of randomized, controlled trial on a significant number of test subjects. In fact the AJCN researchers did nothing of the sort. They simply went into PubMed (the medical online database) and searched for any prior studies that have been published on the blood type diets.

Not surprisingly, they didn’t find any. Had they contacted me prior to the study I could have saved them a lot of extra work. I’ve looked high and low and also never found one. That’s how original this theory is.

Since I became interested in the ABO blood groups three decades ago I’ve collected, archived and categorized virtually every scientific article on blood types (excluding the large number of articles that dealt solely with transfusion) going way back to the early twentieth century. I also own many articles in languages other than English, some of which I have paid to have translated. Finally, my collection includes a large number of articles written in the years 1940-1966, long before the time when medical articles became electronically indexed. And I fully concur with the researchers, that there is indeed not one article of value in all that time that ever linked anything regarding a person’s blood type with nutrition. It is no great news to hear that there is a lack of published studies on following a diet based on one’s blood type: I’ve proselytized for just these types of studies for over two decades. All the authors did was conclude, as did I many years ago, that there is a lack of direct research on the subject.

But here is where the dishonesty begins.

There is a big difference between an absence of evidence and evidence of absence. There is good science behind the blood type diets, just like there was good science behind Einstein’s mathmatical calculations that led to the Theory of Relativity. However Einstein’s theory required very specific and particular conditions to occur (solar eclipses at a certain time in a certain part of the world) before it could be subjected to testing and confirmation.

Just like Einstein’s math, the theoretical and empirical evidence behind the blood type diets is pretty good. Spend some time reading my books or this blog and you will understand. ABO blood type is a significant influence on the digestive tract, from stomach acid levels to intestinal enzymes to the particular strains of bacteria that grow inside of us. Much of the immunologic reactivity of many foods varies by blood type.

The connection between blood types and food lectins was universally maligned, except by some very accomplished lectin scientists, who obviously knew better. Especially vicious were the ‘paleolithic diet experts,’ who then conveniently rediscovered the lectin connection when it became evident that it could be used to justify their grain-phobic worldview. Virtually every skeptic I’ve ever discussed the theory with was completely ignorant of these facts, despite the notion that virtually all of the original studies (minus the pre-1966 stuff) can be perused on PubMed.

The biggest garden gnome in the world, in Nowa Sól, Poland  (Wikipedia)

The biggest garden gnome in the world, in Nowa Sól, Poland (Wikipedia)

The delightful fantasy that everything in modern medicine has a strong evidence basis is just that–a delightful fantasy. For example, many medical agents are often employed ‘off-label’ for uses other than those originally intended as a result of their original study –even if they lack the high degree of scientific scrutiny are routinely reserved for pharmaceuticals. [1] Most herbal medicines, many used successfully since antiquity and the basis for many modern drugs, also have a weak evidence basis in modern science. About 30% of drugs prescribed to children have never actually been tested on children. We continually live and work in a world of knowledge insecurity, typically for the very same reasons you don’t see any studies on blood types and nutrition: Little institutional interest and even less available money.

Long-term diet studies are renowned for their difficulties. Subjects would have to follow a prescribed diet for a significant period of time, perhaps as long as one year, as many of these differences would be rather slight in the short term. Other subjects would have to follow a control or ‘sham’ diet. Both groups would have to include a reasonable number of subjects, and since we are talking about comparing outcomes between the four basic blood groups, we’d have to take this total number of subjects and then quadruple it. Subjects would have to be paid, constantly monitored, and their food prepared and supplied to them. Since we are studying a complete food plan, versus a single food or even a single drug, the cost of doing an ongoing study of this sort would be enormous.

So what is empirically self-evident when employed on a day-in, day-out basis, (“Hey Doc, three weeks on the diet and my psoriasis is clearing up!”) becomes an uncontrollable, insupportable, unsustainable mess when subjected to what is normally the scientific gold standard; a paradigm much better suited for a clean, get-in, get-out, trial of a single agent or intervention, like a drug or a specific medical procedure.

We’ve done some very simple polling (for which I make no special claims to be scientific) that show that, in a rather large number of internet responders, the level of satisfaction following one of the four blood type specific diets runs consistently at about 85% across all four blood types. What made this observation interesting is not the degree of satisfaction, since that is subject to bias, but rather the constancy of that number across the four different blood type groups, especially since they are all following diametrically differing diets to a certain degree.

So, are the headlines truthful? Do the diets not work? Is there no science behind them?


A sure sign that things are turning jaundiced occurs when the registered dietician gets wheeled out for the requisite Parthian Shot. As is expected, the preferred slur here is ‘fad diet’ which is a truely ludicrous accusation since the main book about the blood type diets, Eat Right for Your Type has been in mass publication for almost two decades. A two-decade old fad. One can only wonder just how long something has to be around before it is no longer a fad. Now, with all due respect, your average dietician is simply in no position to comment on the technical basis of how blood groups influence digestive physiology. Sorry, but it’s advanced, high level glycomics/glycobiology stuff and they just don’t do that in these types of programs.

On the up-side, each of the specific diets recommended for each of the blood types is, in itself, a pretty healthy diet. Indeed, somewhere in the nutrition literature, someone is claiming that the scientific evidence supports the use of such a one-size-fits-all diet in everyone. Perhaps the only reasonable claim is that the blood type diets can help predict which healthy diet, among the many out there, is particularly healthy for you.

Should this type of study be performed? Absolutely. But unfortunately, every once in a while there comes along a theory that must remain, at least for the foreseeable future, as a simple thought experiment; a heuristic; a useful rule-of-thumb for those willing to try it. Sort of like chicken soup for a head cold.

Does this lack of ‘evidence’ bother me? Not really. In fact, I’ve moved on from my obsession with the ABO blood groups years ago, although I still keep an eye on new developments.

“Science.” so the quote goes. “If you’re not pissing people off, you’re doing it wrong.”

So I guess the Blood Type Diet is scientific after all.

gnomic, gnomical
1. (Literary & Literary Critical Terms) consisting of, containing, or relating to gnomes or aphorisms
2. (Literary & Literary Critical Terms) of or relating to a writer of such sayings

  1. Walton SM, Schumock GT, Lee KV et al., “Prioritizing future research on off-label prescribing: results of a quantitative evaluation,” Pharmacotherapy 2008; 28(12):1443-52.

9 responses so far

9 Responses to “Gnomic Advice”

  1. John says:

    Brilliant Man, I follow the Diet and it is amazing. Scientific lol , who cares, it works!

  2. Rhonda says:

    The people who shout the loudest are usually the emptiest barrels. The proof is in the pudding. Several members of my family is blood type O and we have all proven it for ourselves individually across borders, generations and gender. Simply, it is the most effective method that has automatically addressed things from rashes, acute long term sinus allergies, automatic weight loss without trying , and accelerated weight loss with even minimal exercise, to sweet cravings and lack of energy, tired legs syndrome and sleeplessness. Energy levels are so high that it makes it almost impossible not to exercise and the cravings for proper foods are increased and garbage foods are naturally a disinclination.
    Say what they will, I tell everyone about D’Adamo, Blood type diet, non diet way of life that makes life better without hardly trying. Its just ‘avoid’ the stuff that shuts your system down and acts like a poison. Simple.

    In our information era, with everyone so so busy, who has time for the various processes of ‘dieting’ that make you feel like its a crime to eat food at all, thus making matters worse. Its a matter of food sensitivity. Some people die from bee stings other people don’t. sensitivity levels are drastically different. Same with foods and blood types.

    And for the record, recently gained 30 lbs from improper eating, the switch flipped and I said enough and being tired and hungry. Stopped the avoid foods, for the most part, and lost a pound a day for three weeks. Proof in the pudding baby!

  3. G. Alan Trimble M.D. says:

    Not only is there science behind the ABO diet, there is also a lot of money.

    • Ula says:

      Yes, a lot of money! lol! I invested an equivalent of 10 dollars in a book (I live in Poland). Guess how much my parents and I spent on my allergy drugs and vaccines during my 30 year struggle (and with miserable effects)?

      I talked to some MD in Poland about the diet and all of them told me there must be something in it. But trying to convince other people is really difficult. Belief in modern medicine with all it`s drugs is too strong. You risk nothing with the diet and nobody tells you not to take your medicines. But after some time they just turn out to be unnecessary.

  4. Thanks to Peter and the discerning who can disclose the spin on systematic reviews that could have supported the proper clinical trials needed to evaluate two decades of empirical evidence.

  5. T. Dan Tollesons says:

    Why is the BTD not receiving the credit that it so obviously deserves?

    It’s not just a “lack of scientific studies.” There’s also a modern psychological fact at work here.

    In 2000, I first became aware of the BTD and carefully read the ER4YT book. Having learned these previously unknown physiological facts about blood type and diet, whenever health and diet have come up in casual conversation WITH ANYONE, I have mentioned the physiological mechanics of the BTD to anyone who seemed willing to listen. I have carefully explained that because of physiology – different blood types benefit from or react to different foods, the variety of natural stomach acidity in different blood types has a direct bearing on the ability of each blood type to digest meat, etc., etc. – each blood type has certain beneficial foods and certain “Avoid” foods.

    Did the physiological facts receive the acknowledgment they deserve from the listeners?

    In a word, “No.”

    Having made a sincere effort to explain the distinct advantages of the BTD to acquaintances, friends, and family members, I can now say, without exaggeration, that NOT A SINGLE PERSON I have explained it to – over all these years – has taken it seriously. Oh, they acknowledge my enthusiasm for the benefits of the BTD . . . but they don’t take me or it seriously.


    I’m sure there are plenty of excuses. “You’re not a medical doctor.” “You’re just trying to sell me something.” “If this were true, I would have read about it on the front page of the newspaper.”

    But it finally dawned on me, this last Labor Day weekend, that there is something more at work.

    One of my sisters was telling me about several nutritional books she had recently purchased. In the past, I had patiently tried to explain to her the decisive advantages of the BTD. Again, I made the same arguments, based on physiology, and testable by trying the diet.

    Her response is very instructive: “I don’t want to be ‘l-i-m-i-t-e-d’ by a diet. I want the full nutritional value of each food.”

    So, she doesn’t want her Type A body to be “l-i-m-i-t-e-d” by a diet that would rule out certain demonstrably detrimental foods.

    Never mind that her stomach naturally does not produce enough acid to digest most meats. Never mind that several foods react negatively with her Type A antigens. She doesn’t want to hear about that.

    But wait – I believe that there’s something more to her response than mere, run-of-the-mill, stubborn blindness. There is something psychological and, indeed, philosophical behind that stubborn blindness.

    We live in a time when most Americans – nominal “Christians” though some 80 percent claim to be – have forgotten God. Other ideas have spread to fill that moral and religious vacuum: pantheism and solipsism. Pantheism is the idea that God – far from being the Creator of the rest of the universe – simply IS everything. Solipsism is the idea that we can create our own “reality” – just as the Creator God was said to have created the universe.

    If you immerse yourself in those two ideas – pantheism and solipsism – then, not only can you create your own “reality,” but you can also ignore any ideas that conflict with your “reality.”

    Therefore, if you don’t like the “limitations” that a particular diet places on you . . . you can simply ignore that diet, and adopt whatever diet fits with your “reality.” Physiological facts – since they originated with somebody else’s “reality” – don’ t have to apply in your “reality” if you don’t want them to.

    As I think you can see, solipsism is the very epitome of wishful thinking.

    Not all Americans are pantheists or solipsists – but I think the above observation goes a very long way toward explaining the undeniably widespread resistance to the discovery of the BTD, as well as the Genotype Diet.

    For what it’s worth, Dr. D’Adamo, I believe that you – standing on your father’s shoulders to develop, publicize, and implement both the Blood Type Diet and the more refined Genotype Diet – have made the most important nutritional discoveries since vitamins were first identified.

    And I thank you very much for doing that.

    T. Dan Tolleson

  6. mims says:

    Stanford is doing research looking at specific genomic markers to assign test subjects into one of four different types of diets (Ornish to Atkins to Zone)

    http://nutrition.stanford.edu/projects/az.html. This first trial randomly assigned women to a diet and the results were a wash. But when they after the fact looked at genetic markers they saw the subjects who did have success were following a diet that worked for them genetically. They are now redoing the study but assigning them a diet based on genetic markers. IT would be so much cheaper to do this study just looking at blood type. http://nutrition.stanford.edu/projects/DietbyGenotype-Study.html

  7. Matthew E says:

    It’s certainly possible to contact the participants in the original study and get their blood types. A public request for cooperation from a reputable research organization would not be turned down or ignored. Then the impact of the diets could be correlated to blood types. And we’d have a test that met the ‘golden standard’. And it would cost a small fraction of what a fully independenty run ‘gold standard’ study would.

    I challenge you to do it.

    NCCAM would be an appropriate source for the relatively minimal funds needed.


    • What are you talking about? What original study? Whose blood types? The AJCM article did no direct testing. They just did a literature search looking for prior studies and found none. Thank you for your suggestion that I just dial up a few research departments and ask them if they want to do some research with me. I’m sure that would be a worthwhile pursuit. ‘Relatively minimal funds’? You’ve obviously never done biochemical or nutrition research; researchers routinely lament the expense and operational overhead when testing even one nutritional agent/intervention over long periods of time in large populations. Thanks for the feedback, but get real, dude.