Nutrition Hotline
By Reed Mangels, Ph.D., R.D.
Our advise? Stick with a varied, whole foods-based
vegetarian diet regardless of your blood type.
QUESTION: Have you heard about the book which pushes blood types as determining whether somebody should be vegetarian or not? C.S., MD
ANSWER: The idea of choosing foods based on your blood type was popularized by Peter J. D'Adamo, ND, in his book, Eat Right For Your Type (G.P. Putnam's Sons, 1996). D'Adamo, a naturopath, proposes that those who have blood type A should be vegetarian, while those with blood type O must eat meat and eliminate wheat and some other grains. He says that following the correct diet for your blood type will help you maintain optimal health and weight, avoid many infections, and fight back against life-threatening illnesses. Is there any truth to his claims?
While D'Adamo spends more than 350 pages explaining the minute details of the foods, supplements, medications, and exercise regimens which should be followed by people with each blood type, he fails to scientifically document the effectiveness of his recommendations. Many of the claims which he makes are not backed up by published research. For example, depending on your blood type, you are presented with detailed lists of foods which are highly beneficial, neutral, or to be avoided. How were these lists generated? Has any research been published showing adverse health effects from use of foods which should be avoided? No studies are presented which support what appear to be the author's speculations.
Numerous studies have shown that vegetarians live longer than non-vegetarians and have a lower risk of a number of chronic diseases. These studies are likely to be based on people from all blood type groups. It certainly seems that a vegetarian diet has benefits for those studied, regardless of their blood type. Similarly, studies like those of Dean Ornish appear to demonstrate the beneficial effect of a vegetarian diet and other lifestyle changes on a number of individuals, and not just those of a certain blood type.
Eat Right For Your Type should not be used as the basis for dietary change. Statements like "I could never be a vegetarian, I'm type O" are not based on scientific evidence and may even lead people to avoid making dietary changes which could benefit both their health and the health of our planet. Our advice? Stick with a varied, whole foods-based vegetarian diet regardless of your blood type.
