Blood Typing Your Diet?

I've been getting some questions lately about whether or not eating accordingly with your blood type is a good idea. Honestly haven't spent any real time exploring this, or what it means in terms of diet, so had to do a little research and think about it for a second. If we start by looking at the different blood types and what Dr. D'Adamo, the blood type diet's guru, says about them in relation to diet and exercise:

Blood type O is the oldest blood type. O-people will thrive on a diet rich in animal proteins, while minimizing dairy and grains. Ideal exercise routine should be based around aerobics, martial arts, contact sports and running.

Type A-people should consume a vegetarian, whole foods based diet. Exercise routine should be focused on calming movements, so yoga or tai chi would be good options. Apparently A-people are also prone to cancer, diabetes and heart disease, according to Dr. D'Adamo.

Type B's are robust people with solid immunity, and a tolerant digestive system. B-people should eliminate corn, wheat, buckwheat, lentils, tomatoes, peanuts, sesame seeds and chicken if they're trying to lose weight. Foods that encourages weight loss are green veggies, eggs, beneficial meats (goat, lamb, rabbit, mutton and venison), and low fat dairy. For exercise, hiking, cycling, tennis and swimming are suggested as good activities, as it requires mental balance.

The last one, type AB, Dr. D'Adamo claims to be the most recent blood type (in terms of evolution), and foods to avoid for these group of people includes caffeine and alcohol (especially in stressful situations, go figure). Foods to focus on should be tofu, seafood, dairy and green veggies if you're trying to lose weight. For exercise, a combination of what's suitable for type A and B are recommended.

Obviously there's a lot more details than what I listed above, so if you want to dive in, website is right here. But just this small part makes me tick a little, it goes against what I've learnt from an evolutionary perspective. First of all, type O is not the oldest blood type, and it didn't evolve through dietary patterns. Type A seems to be the oldest type, but who knows? And does it matter? Recent research points to types A, B and O being about 20 million years old, and if we think about this...how can type A, or any blood type require foods that hasn't been around for more than 10,000 something years? Makes no sense in my head. Also, being a Scandinavian, I've got to question this from the aspect of the diet of the Sami people. The majority of these fine folks are type A's (50-90%!), yet their diet was (is) reach in reindeer meats, blood, and fatty fish, and they are healthy. 

A lot of the focus with this diet is based on the idea that lectins found in certain foods will cause clumping of the red blood cells, and that this is different depending on food and blood type. However, no such evidence exists. What research has shown is that lectins that causes this type of clumping will do so regardless of blood type. I think people who get great results on this diet can attribute it to the fact that it seriously reduces the amount of processed foods they're consuming, no matter the blood type. I don't think it's optimal, but hey, whatever works, right? I'll keep doing some research and maybe I'll change my mind. We'll see. If I find something interesting I'll for sure write a little something about it here.