3 Dec 2009
You have no room to be criticizing Dr D'Adamo's work with blood types and disease.  You have a PhD- very impressive.  Dr D'Adamo has been practicing medicine in his clinic for more than 20 years, and has watched tens of thousands of patients heal on his nutritional plan.  I have a library of research that I keep on hand, mostly from PubMed, that backs up everything Dr D'Adamo says. 

You can find dozens of articles on MEDLINE that review the blood type specificity of lectins found in fruits, nuts, fungus, and animal flesh. 

I find it sadly disturbing to hear "professionals" yammer away about Dr D'Adamo's "pseudoscience", while contributing nothing themselves to the art of healing. The science is there. The research is clear. If you don't believe me, I can send you a DVD. Either way, Robert, I hope you will learn to have more respect for those who are changing lives, as opposed to filling them with doubt. 

Regards, 

Eric Morrison
www.battleforhealth.com

reply: D'Adama is a naturopath. To say he practices medicine is a stretch. Also, I notice on your website that you write: But most importantly, your personal story with the Blood Type Diet is what matters!

You say you have a library of research from PubMed to back up the blood type diet claims. Bring it on. I searched MEDLINE and didn't find any articles on the blood type diet, but I did get a link to a Mayo Clinic article by Katherine Zeratsky, R.D., L.D. who writes:

Some research suggests that people who have certain blood types may develop specific patterns of food allergies. However, there's no scientific evidence to support the so-called "blood type diet," in which different diets are recommended based on a person's blood type. At this time, eating or avoiding certain foods according to your blood type isn't thought to have any favorable influence on weight or overall health. In fact, a "blood type diet" may not meet your nutritional needs.

I also found an interesting website where Dr. Arpad Pusztai is asked about the use of his data on lectins by Adamo. You should find it disturbing to discover that your hero is misusing the data:

Yes, I know that D'Adamo refers to this Table and everything in it is true. However, it is a general Table in which not everything is valid in all species.

Most of our work has been done in rats as you know in which, obviously, no human blood groups are expressed.

As I said a number of times before very few lectins recognise and react with human ABO blood group sugar structures specifically. If anyone takes the trouble to go through all the entries in our book it ought to be plain to them that most lectins are not strictly blood group specific. They may react with the blood group epitopes, but not specifically.

For example, the main human B blood group determinant is galactose and obviously all galactose-specific lectins will react with it. However, as 95% of all galactose-specific lectins will also react with N-acetylgalactosamine that is the determining sugar in blood group A, these lectins cannot be human blood group specific. I hope this is clear. As far as I am concerned there is some truth in what D'Adamo says but the whole situation is far more complex than he or others can imagine.

The method you and D'Amamo espouse — intuition and anecdotes give you your base, then you look for any kind of scientific work that others have done and try to use it to confirm you bias — is not the best method if what you seek is the truth.

Eric Morrison replies [The whole reply is too long to reproduce here, so I've excerpted key points. Eric lists hundreds of published scientific papers as evidence for his position. RTC]

....You'll remember from your undergraduate physiology class that gastrin is the hormone that stimulates the production of hydrochloric acid and pepsinogen in the stomach, which work together to make pepsin. Pepsin is the enzyme that breaks down protein. So if these studies are showing that type Os make more pepsin, it would make sense that Os do better to eat meat than As.

reply: No, it wouldn't. Almost every food contains protein: nuts, peanut butter, seeds, beans, lentils, soy products (tofu, soy milk, tempeh), grains (wheat, oats, rice), eggs, vegetables (a cup of broccoli has 4 grams of protein), and dairy products all are good sources of protein.

As long as As make enough pepsin to break down whatever proteins they ingest, there is no need for As to cut out or cut down on meat.  It would be absurd to assume that everyone with type O produces plenty of gastrin or that everyone with type A doesn't produce enough to warrant eating meat as a primary source of protein. There may be good reasons for eliminating meat (or dairy products or other types of food) from one's diet, but blood type isn't one of them.

Another one of the founding discoveries made by Peter D'Adamo during his time in medical school was that Os had a significantly higher rate of peptic ulcers, while As had more stomach cancer. Believe it or not Bob, our beloved Dr D'Adamo didn't exactly believe in his father's ideas about blood type dieting either. He was convinced when he did the research and found astonishing correlations to blood types and diseases.

reply: It may be true that Os have more ulcers, but these ulcers are caused by bacteria and are not related to diet. As may have more stomach cancer and stomach cancer may be related to diet, but it is a logical leap to claim it is because As don't eat the A-type diet that they have more stomach cancer. Just because blood type and diet correlate to different types of cancers does not imply that the blood-type diet would have any effect on the ABO cancer rates. What you need to produce is a long-term study of a large random sample of people who have followed the blood-type diets so you can compare their cancer rates to the general population of ABO types.

It's true that certain groups of people, due to their evolutionary history, share a common blood type. Many people with the same evolutionary history have remained in the same geographical area for millennia. In some of those areas, certain types of cancers or other diseases may be significantly greater than in other geographical areas. It may also be true that diet is a significant factor in the development of certain cancers or diseases. But it doesn't follow from this data that blood type is a significant causal factor in the development of any of these cancers or diseases or that the dietary factors that may influence these illnesses has anything to do with blood type.

Antigens:

I bet you didn't know that foods also have blood type, Mr. Carroll. Your blood type is just a small piece of sugar that sits on the outside of your cell. If your sugar is fucose, that makes you type O. If it's fucose covered in N-Acetyl galactosamine, you're type A. If it's fucose covered in D-Galactose, you're type B. Your body makes antibodies against whichever of these sugars you don't produce on your own, which is why a wrong transfusion can kill you. The antibodies clot the sugars together, meaning your immune system has a better chance of doing its job. This part is common sense. If you introduce antigens in your blood stream that you make antibodies against, your body will reject them. So if you're type O or type A and you drink milk, you're absorbing the D-galactose from the milk, which your blood type naturally opposes.

reply: As you remember from your undergraduate nutrition class, mammalian milk contains lactose which in turn is made up of D-galactose and D-glucose. If I suckled at my mother's teat, I ingested D-galactose no matter what her blood type was. By your logic, no human with type A blood should drink breast milk, a position I find a bit at odds with the data.

Anyway, I'm type A and have been drinking cow's milk for over 60 years with no obvious adverse effects.

As you remember from your undergraduate pharmacology class, dose makes all the difference. The amount of D-galactose in pasteurized cow's milk isn't going to harm me any more than the D-galactose in my mother's milk harmed me as an infant.

Lectins:

Lectins are proteins found in foods that can cause a number of problems in the human organism. It wasn't Dr D'Adamo that discovered them either; it was Hermann Stillmark of the University of Dorpat in 1888-- the one that discovered the poison Ricin, which is a lectin from castor beans. Then in 1908 Karl Landsteiner, who discovered ABO blood types, noticed that lectins from lentil beans would clot together rabbit red blood cells, without doing anything to pigeon red blood cells. It was then William Boyd of the Boston University School of Medicine who found that lectins are blood type specific. For example, he discovered that lima bean lectins clotted together type A blood cells, but not type O cells....A "considerable amount of work" has been done on the study of lectins. They are known to bind together red blood cells, and their blood type specificity is no secret.

reply: My editor, John Renish, notes that the assassin who killed Bulgarian dissident Georgi Markov in 1978 by injecting him with ricin didn't need to know Markov's blood type.

You should note that lectins can also serve very important and useful biological functions. Anyway, I'll quote Dr. Pusztai again:

....very few lectins recognise and react with human ABO blood group sugar structures specifically. If anyone takes the trouble to go through all the entries in our book it ought to be plain to them that most lectins are not strictly blood group specific. They may react with the blood group epitopes, but not specifically. For example, the main human B blood group determinant is galactose and obviously all galactose-specific lectins will react with it. However, as 95% of all galactose-specific lectins will also react with N-acetylgalactosamine that is the determining sugar in blood group A, these lectins cannot be human blood group specific.

Also, just because lima bean lectins clotted together type A but not type O blood cells in vitro does not mean that lima beans should or shouldn't be eaten by various blood groups. My mother used to serve lima beans on a regular basis. I loved them and never suffered any ill effects from them.

You see, this is why it amazes me that people still don't believe Dr D'Adamo's work is based in science. You have to try hard not to realize how much research has gone into his work.

reply: I call D'Adamo's work pseudoscience rather than science not because he doesn't cite scientific papers to support his beliefs. He does. But he misinterprets the data and draws inferences that are not justified from the data. He also cannot point to a single RCT or prospective study that demonstrates any of the claims he makes about the ill effects of not adhering to a blood type diet and the beneficial effects of following a blood type diet. He cherry-picks scientific studies and makes unjustified assertions based on those studies.

No, the Blood Type Diet is not accepted by the majority of mainstream medicine. I understand that; yet, AMA acceptance should not be a meter of medical magnitude.

reply: I agree. AMA acceptance is irrelevant to the value of the blood type diet, but so is the listing of dozens of studies that support completely different points from those made by D'Adamo. Also, for the record, my editor John Renish tells me that "the AMA has only about a third of all physicians as members and is primarily a lobbying organization, rather than one that controls the practice of medicine. Its only tie to questions like blood-type diets is that its journal has an independent editorial staff that accepts only about 10% of all papers submitted for publication."

There is one medical doctor who summarizes it best:

"When I first heard of Peter D'Adamo's blood group diet, of course I was very skeptical: Should we have missed in our book (Prokop/ Uhlenbruck: Human Blood and Serum Groups) such an important aspect? But years later, my interest switched to the nutritional field while working on the so-called metabolic syndrome, my interest increased in studying the role of genes in metabolic processes. I found out, that Peter D'Adamo's blood group orientated diet could probably be a first step in the right direction. I am afraid that Peter's merits are not estimated enough in the scientific world. Therefore it seems to me necessary, not only to promote his concept here in Europe, but also to tell him that I acknowledge him as one of the most creative scientists in the Western world."

- Professor Gerhard Uhlenbruck, PhD, MD Director, Institute for Immunobiology, University of Cologne

If you wish to play the quote game, I can find thousands to support my side. But this isn't about feelings or beliefs, right? I don't think it comes down to which respectable physician has a stronger opinion, because that's not scientific. If you wish to cherry-pick your sources, that's fine. Feel free to pick through this modest list. You wanted me to "bring it on", so here you go.

reply: I won't post Eric's list, but it is so long that if I spent every waking moment reading his references I would have to live another twenty years to complete the task. Here are three chosen randomly:

Greer F, Pusztai A Toxicity of kidney bean (Phaseolus vulgaris) in rats: changes in intestinal permeability. Digestion 1985;32(1):42-6

Mourant AE Blood Types and Disease Oxford university Press 1979

Visek WJ Arginine needs, physiological state and usual diets. A reevaluation. J Nutr 1986 Jan;116(1):36-46