According to naturopath Peter J. D’Adamo, blood type is a genetic fingerprint that is more powerful than race, culture or geography. The mechanism of action involves lectins which are a diverse group of proteins present in certain foods. The author claims that negative reactions between food lectins and our blood type are responsible for many ailments. This is due to the fact that lectin and Blood type interactions cause agglutination or build-up of blood cells in the tissue. His solution is to avoid the foods that contain the negative lectins, and as such, eat according to a specific blood type.
- Type O’s (46 % of the population), belong to the oldest genetic group and need to eat meat virtually every day to satisfy ancient, hunter-gatherer genes. Type O’s should also avoid oats, wheat, and most grains, because they are all products of an agriculture that didn’t exist when O’s originated.
- Type A’s (40% of the population) evolved after the start of agrarian society and are best off as a vegetarian.
- Type B’s (10 % of the population) emerged as humans migrated toward colder, harsher climates. Bs’ can have the most varied diet, including meat, and theirs is the only blood type that does well with dairy products.
- Type AB (4% of the population) is a relatively modern adaptation that arose from the intermingling of the A’s and the B’s. Therefore, AB’s have the benefits and intolerances of types A and B.
- Many see health improvements and/or weight loss based on positive improvements made to their diet and lifestyle.
- There is a focus on home cooked meals and avoidance of processed food and refined carbohydrates.
- The plan encourages exercise.
- No evidence currently exists to validate the proposed health benefits of blood type diets. Observational studies have demonstrated there are links between ABO blood types and an increased risk of certain diseases. However, a systematic search of the literature found a lack of evidence that blood type diets result in better health outcomes and a reduced risk of developing diseases associated with the blood types. Despite the popularity of the blood type diet in the lay literature, the evidence-based literature does not substantiate these claims.
- Restriction can lead to boredom, a common drawback of ‘diets’ – making the plan difficult to sustain.
- May experience nutritional deficiencies (supplements are recommended).
- Places too much emphasis on blood type alone and fails to take into account individual differences
- Preferences & health challenges could result in a very small variety of foods included in the diet – this affects overall nutritional status and could lead to nutritional deficiencies
- Complicated if members of the family/household have different blood types.
Does the Eat Right for your Blood Type Diet really work, or is it just another Fad?
Dietary lifestyles should be informed by evidence-based, individualised nutritional requirements. A statement often repeated in “Eat Right 4 your Type” is that one’s dietary approach must be individualised. However, the author then, instead of offering one solution, offers….FOUR solutions to the 7 Billion people who make up our world. Is that individualised? I think not. The concept would make perfect sense if all individuals with the same blood groups suffered from the exact same medical disorders, had the same nutritional needs, and needed the same medications, but that is obviously not the case. The diet would also benefit from some sort of histopathology evidence of lectin build up in the tissues. But alas, there is none. As a result, it’s handy to look at the Blood Type Diet as something similar to a horoscope – there are going to be traits or predictions that apply to you but this does not necessarily mean that every single guideline is perfectly individualised. Rather, focus on an eating plan that is balanced and specific to your lifestyle in order for it to be both practical and sustainable.