Eating Right for Your Blood Type

| by Nicole Crites | On Barnes & Noble’s official website, more than 12,000 diet and nutrition books are available for purchase. Thousands of different plans, thousands of doctors, each claiming that his or her way is the right way. But what if the right way actually depends on your blood type?

In 1997 Dr. Peter D’Adamo published Eat Right 4 Your Type: The Individualized Diet Solution, which introduces four different diets each designed for specific blood types. Despite many criticisms against his research, the book became an international bestseller with 7 to 8 million sold, translated in more than 50 languages.

D’Adamo said that years of research led him to conclude, in a nutshell, that the genetics of each blood type differ from one another so significantly that it affects a person’s health, stress, and how he or she digests certain foods, so diets should be tailored to fit his or her type.

“There’s evidence that blood types have differences in how they react to foods,” he said, “because things that are part of what gets turned on and off when we get our specific blood type influence the levels of certain enzymes we have in our digestive track.”

For instance, he said if a person is Type O, he or she manufactures three-and-a-half times the enzyme that helps break down cholesterol and fat. Whereas, those with blood type A make very little of the enzyme. So he recommends a high-protein diet for Type O, and for those with Type A, a meat-free diet based on fruits, vegetables, beans and whole grains.

“How could we say that telling somebody to eat a balanced diet is the best piece of advice when we have evidence that the very enzymes you need to break down the fats, cholesterol and meat vary three-fold just by that simple genetic determinate, that one gene,” said D’Adamo.

He said that his diets are not strictly weight-loss plans, but rather a food-as-medicine type of approach that can assist in coping with stress as well as helping diseases. He said long-time users of the diet have even reported improvements in autism, multiple sclerosis and thyroid function.

Lisa Hall, a registered dietitian and dietitian manager at Cancer Care Services, said she would professionally recommend against a pro-blood type diet because there is a lack of scientific evidence.

“There are no known well-designed studies that can prove that eating certain foods for your blood type will aid in digestion more efficiently or facilitate weight loss more effectively,” she said.

Hall said her opinion is that the dietary guidelines in D’Adamo’s book would be an overall improvement for the general population no matter what their blood type. If someone experiences weight loss or improvements in health, it is probably just because he or she is eating healthier foods in general.

A 2013 study in the American Journal of Clinical Nutrition examined data from over one thousand studies and did not find a single well-designed study looking at the health effects of the blood type diet and concluded “no evidence currently exists to validate the purported health benefits of blood type diets.”

D’Adamo said he has researched hundreds to thousands of scientific studies and literature on the subject in addition to thoroughly studying glycobiology, genetics and more, and strongly defends his findings on the effects of different blood types.

Type O
High-protein diet, heavy on lean meat, poultry, fish
Light on grains, beans and dairy
Leading reason for weight gain among Type O’s is gluten
Ideal exercises include aerobics, martial arts, contact sports, running
Tendency toward high levels of stomach acid
Type A
Meat-free diet based on fruits and vegetables, beans, whole grains
Ideally organic and fresh because Type A have a sensitive immune system
Can derive significant benefit from calming, centering exercises like yoga and tai chi
“With this diet you can supercharge your immune system and potentially short circuit the development of life-threatening diseases”
Type B
Robust immune system, tolerant digestive system
Avoid corn, wheat, buckwheat, lentils, tomatoes, sesame seeds, peanuts and chicken
Eat green vegetables, eggs, certain meats (goat, lamb, rabbit, venison) low-fat dairy
Moderate exercise requiring mental balance such as hiking, cycling, tennis and swimming
Type AB
Focus on tofu, seafood, dairy and green vegetables
Avoid caffeine, alcohol, smoked or cured meats
Recommends smaller, more frequent meals to counteract digestive problems caused by inadequate stomach acid and peptic enzymes
Pay attention to combining certain foods. For example, you’ll digest and metabolize foods more efficiently if you avoid eating starches and proteins in the same meal.