If you follow popular diets, or even if you don’t, you’ve probably heard about the blood type diet. The book Eat Right for your Blood Type has over 7 million copies in print and is written in 50 languages. In other words, it seems as though this plan has been read and followed by A LOT of people. With so many diet plans out there, it’s tough to weed through what’s worth it and what’s not. We dove deep into what this plan is all about and emerged with the facts for you.
What it is
The Blood type diet was created about 15 years ago by naturopath Dr. Peter D’Adamo, and is centered around the idea that you should eat, exercise, and live, according to your blood type. By doing this, Dr. D’Adamo says you will be healthier, have less disease risk, lose weight, and feel better. D’Adamo’s basis for this diet? He pairs each of the four blood types with various points in human evolution. It’s suggested that you eat according to how your ancestors ate when your specific blood type evolved.
For instance, if you have blood Type O, the oldest blood line, you’re instructed to eat the way that hunters and gatherers ate (mostly lean meats, vegetables, and a few fruits; avoid grains, dairy, caffeine, and alcohol), all of which are said to be triggers for digestive and health issues in Type Os. Type A blood? You’re body is pre-programmed to love a vegetarian diet, while Type B’s must avoid specific foods such as corn, wheat, buckwheat, lentils, tomatoes, peanuts, sesame seeds, and chicken. If you have the youngest blood line, AB, you’re basically the love child of your blood type A and B parents, and thus, should follow a diet comprised of recommendations from the two, depending on the circumstances. Type AB recommendations include avoiding caffeine and alcohol, while noshing on foods such as tofu, seafood, dairy and green vegetables if you are trying to lose weight. AB is the only blood type whose plan includes certain types of dairy (yogurt and kefir.)
Any plan that cuts out entire food groups without many evidence-based reasons raises a red flag. This diet plan takes a mixture of history and biology and turns it into a far-fetched diet plan. While this certainly makes for interesting reading and a nice history lesson about the migration of our ancestors, there are many holes in the logic for this diet plan. The results related to the diet have not been reproduced by any sound research. Just because our blood types evolved at certain times in history, doesn’t mean that thousands of years later our bodies require only the foods that were available at those times. In many instances, D’Adamo applies scientific concepts out of context to how they work in the diet. For instance, in reading one of D’Adamo’s rationales for Blood Type B, D’Adamo says the following: “Type Bs should avoid chicken. Chicken contains a Blood Type B agglutinating lectin in its muscle tissue. Although chicken is a lean meat, the issue is the power of an agglutinating lectin attacking your bloodstream and the potential for it to lead to strokes and immune disorders.” When you dig through the long scientific terms in this sentence, it translates to this: a type of protein found in chicken can cause your blood to clot too much, therefore increasing your risk of stroke. While this may be true if the protein lectin was able to go straight to your bloodstream unchanged, that is not the case. When you eat chicken (or any other protein-containing food) the protein in it gets digested and broken down into many little parts (amino acids) thanks to numerous enzymes and stomach acid. By the time it hits your bloodstream, it’s no longer in the lectin form and wouldn’t have the same effect. This is just one example of how something derived from a true biologic process has been manipulated to a point that is no longer accurate.
Another downfall of following the blood type diet is that it’s considerably inconvenient for families with all different blood types to follow completely different diets. This is 2012 after all, not 900 AD. And finally, D’Adamo recommends supplements to replace some of the nutrients you’ll be missing out on while following the plan for your blood type — another big red flag. Why not just eat the foods that would give you those nutrients?
Are there any benefits?
The blood type diet forces you to take a good look at what you eat, which is an eye-opening experience and will typically motivate change. In addition, the diet plan for all blood types restricts processed foods, especially those with added sugar and refined flours, a change that will result in weight loss and more energy for most people.
Should you follow it?
No. But there are some good things to take away from it. Start keeping track of what you’re eating, eat mostly whole unprocessed foods, lots of veggies, lean proteins, whole grains, and calcium-rich foods. If you are having digestive problems, low energy, or other symptoms, talk to your doctor right away. He/she can test you to find out for sure, before you begin to cut out certain foods. And if you feel like some foods just don’t agree with your stomach, talk to a registered dietitian who can help you pinpoint what foods work best for you and which are better to skip based on how you feel, not your blood type.