Why I Don’t Like the Blood Type Diet

I frequently run into people in the health world who are all gung-ho over the blood type diet. This is a diet that divides people on the basis of their blood type – O, A, B, and AB. This diet was developed by naturopathic physician Peter J. D’Adamo, N.D. and popularized in his book Eat Right 4 Your Type.

The O diet: Eat meat (high protein, low carbohydrate). Cut out wheat and most other grains. Engage in vigorous aerobic exercise. Your risk factors for ulcers and inflammatory diseases, such as arthritis increase if you eat incorrectly for your type.

The A diet: You should be largely vegetarian (eating a high carbohydrate, low fat diet). Engage in gentle exercise such as yoga or golf and meditate to deal with stress. Your risk factors for cancer and heart disease increase if you eat incorrectly, according to Dr D’Admao.

The B diet: You should have the most varied diet of all the blood types, one including meat; yours is the only blood type that does well with dairy products. Engage in exercise such as moderate swimming or walking. Your risk for slow-growing viruses that attack the nervous system increases if you eat incorrectly for your type.

The AB diet: You have most of the benefits and intolerances of types A and B, so most foods which are recommended for either type A or B will also work for you. Engage in calming exercises and relaxation techniques. You have the friendliest immune system. (Daily Mail)

What I Do Agree With

The emphasis of the Blood Type Diet is that not everyone responds the same way to the same foods. People are unique. A one size fits all approach to nutrition does not work.  I totally agree with this. That is why many diets do not work well for people long term. We all need to learn to listen to our bodies and figure out what affects us positively and negatively and adapt a diet to fit our body and our life.

What I Don’t Agree With

Despite the emphasis on uniqueness between people, hence the 4 blood types, the diet is not nearly unique enough.  All people with type O do not need to eat the same. When I saw that type O (my type) should not have coconut products that immediately raised a huge red flag with me. Coconut oil is one of the most healthy oils for people to bake and cook with and I certainly don’t see it as a problem for my body.

The theory behind the blood type diet is rooted in evolutionary thinking. I am a creationist and do not believe the underlying premises of evolution. Thus I have a problem with a diet that is coming out of that kind of thinking

From my research Dr. D’Adamo does not really present the solid scientific evidence needed to support his claims. He makes some very significant claims especially about lectins, specifically that lectins cause agglutination in certain blood types. For example, according to D’Adamo, people with B-type blood should avoid chicken because it contains lectins that will agglutinate blood in these individuals, but not in people with other blood types. There is no evidence for this claim. In fact it seems that lectins affect all blood types in the same  manner. (Donmatsz.blogspot.com)

It also does not make sense to say that blood type is what sets different people apart. All humans are essential the same in regards to blood type, gut design, teeth design and number of teeth, enzymes, etc. Scientists have found no relevant anatomical, physiological, or biochemical differences between Chinese and Caucasians or Eskimos. They have not found these kind of differences between people of different blood types either. (Donmatsz.blogspot.com)

Why Some Feel Better on This Diet

When people go on a special diet often it is from a standard American diet that is full of processed foods and other harmful things. So making deliberate choices of more vegetables and less processed foods and sugar can often be significant in helping an individual feel better. But it does not mean the blood type diet is really the cause behind the improvement in the persons’ health.  Rather it is often just general principles of improved eating that are responsible for changes.

So if your health practitioner is pushing the blood type diet on you take it with a grain of salt.  Dietary changes are needed for most Americans, but in my opinion the paleo diet or a elimination diet for improving gut health is a much better place to start.