Blood Type Diet Explained

“Eat Right for Your Type” is a book in which Dr. Peter D’Adamo suggests that our blood type is the most important factor to consider for determining our diet and that the it is highly important to make sure that we consider when choosing our diets.

The problem with this theory however is that it has no scientific basis, and where scientific studies have been carried out they have in fact been unable to prove any benefit exists for using this diet. Here we will look at the idea behind the blood type diet and why we can say with some certainty that it’s not true.

The Basis for the Blood Type Diet

D’Adamo claims that the foods in our diet contain ‘lectins’. These are proteins found in our foods that react specifically with certain proteins present in our antigens. Thus the idea is that it is important to choose certain foods that contain lectins compatible with the antigens in our blood. Thus D’Adamo has identified for each blood type foods that are beneficial, damaging and neutral. So far so logical, but there are problems that the scientific community have identified.


While lectins certainly do exist, the first problem with the blood type diet is that research shows that lectins do not exist in the majority of foods (and not those addressed by the book). Only very few foods such as lima beans contain lectins and this means that you could not experience any of those effects by consuming certain foods or avoiding them. When D’Adamo lists his ‘beneficials’ and ‘avoids’ he does so seemingly at random without giving any explanation as to why those foods were chosen.

D’Adamo makes many unsubstantiated claims in general and in one instant he claims that elderberry can be used as a remedy for the common flu. This has no scientific backing and is misleading and potentially harmful information. Meanwhile he has produced no studies or papers to back his theory and thus none of the claims he makes can be taken as anything more than guesses.

From an intuitive perspective the diet also lacks common sense – particularly in terms of evolutionary theory as we have no mechanism for helping us to determine which foods we should and shouldn’t eat. Seeing as D’Adamo claims this is the most important factor in determining a healthy diet, it seems improbable that we don’t have cravings or something else to help us choose the correct type of food. Furthermore it seems unlikely that we wouldn’t have noticed the ill effects of our diet prior to D’Adamo’s intervention.

Worst of all, following most of the advice recommended by D’Adamo without supplementation would result in nutrient deficiencies most likely – and even if this weren’t the case it would be highly difficult and impractical for a family of different blood types to follow.

Thus it is safe to say that without more clinical trials this is no more credible than astrology or homeopathy, and like the latter it is most likely a scam designed to sell books and promote websites.

1 Comment

  1. The author lost his credibility with his comment on homeopathy.

Leave a Reply

Your email address will not be published.

Recommended Articles