Eat Right For Your Type? No, The Blood Type Diet Is As Useless As Other Fad Diets
    By News Staff | January 15th 2014 08:13 PM | 4 comments | Print | E-mail | Track Comments

    If you tried the martini diet, the tapeworm diet and going gluten-free, science has bad news; the popular blood type diet isn't going to work any better for you. 

    The 'blood-type' diet was popularized in the book "Eat Right for Your Type", written by 'naturopath' Peter D'Adamo. The hypothesis behind the diet is that the ABO blood type should match the dietary habits of our ancestors and people with different blood types process food differently. According to that, individuals adhering to a diet specific to one's blood type can improve health and decrease risk of chronic illness such as cardiovascular disease. The book was unsurprisingly a New York Times best-seller and has been translated into 52 languages and sold over 7 million copies. 

    The researchers behind the study took an existing population of mostly young and healthy adults who provided detailed information about their usual diets and provided fasting blood that was used to isolate DNA to determine their ABO blood type and the level of cardiometabolic risk factors, such as insulin, cholesterol and triglycerides. Diet scores were calculated based on the food items listed in "Eat Right for Your Type" to determine relative adherence to each of the four 'blood-type' diets.

    ‘Blood-Type’ diet (A). Diet score distribution for each ‘Blood-Type’ diet (B). doi:10.1371/journal.pone.0084749

    "Based on the data of 1,455 study participants, we found no evidence to support the 'blood-type' diet theory," said the senior author of the study, Dr. Ahmed El-Sohemy, Associate Professor and Canada Research Chair in Nutrigenomics at the University of Toronto. "The way an individual responds to any one of these diets has absolutely nothing to do with their blood type and has everything to do with their ability to stick to a sensible vegetarian or low-carbohydrate diet." 

    Researchers found that the associations they observed between each of the four blood-type (A, B, AB, O) diets and the markers of health are independent of the person's blood type.

    El-Sohemy says that a previous lack of scientific evidence doesn't mean the diets didn't work - but that is what evidence means. If it isn't shown to work, it's homeopathy or acupuncture or anything else until it is shown to work. "There was just no evidence, one way or the other. It was an intriguing hypothesis so we felt we should put it to the test. We can now be confident in saying that the blood type diet hypothesis is false."

    Last year, a comprehensive review published in the American Journal of Clinical Nutrition found no evidence to support the 'blood-type' diet and called for properly designed scientific studies to address the issue.

    Citation: Wang J, García-Bailo B, Nielsen DE, El-Sohemy A (2014) ABO Genotype, ‘Blood-Type’ Diet and Cardiometabolic Risk Factors. PLoS ONE 9(1): e84749. doi:10.1371/journal.pone.0084749


    This is a great news because it means this issue is out of the question for good (for now, unless another study finds opposite results)

    But I don't understand why you have to mix this question to the Celiac disease once more. What more confusing than that : you admit Celiac is a valid serious question in a certain condition (positively being tested positive), but then you keep presenting the thing on the same page amongst various other ridiculous beliefs, while you still don't acknowledge the fact that Celiac testibility is a real difficulty and concern for many people being more or less simply sensible and intolerant, to the point you present recently a blood test that could really make a difference, without even noticing you're contradicting yourself badly in the sequence in which you present all these stuff one after another...

    To the readers of this blog, the issue with the Celiac thing, Hank Campbell, becomes all yours in a sort of pitiful confusion, and we might as well start asking ourselves if what you're after hitting on this nail again and again with more and more bad faith every time, isn't simply, and sadly, the success of your first outburst last year and its hundreds of feedback comments. Do you really miss this popularity you once had at this point you compromise your sense of objectivity to gain some visibility? It's so common in the world of blogging that people would do so, so what's up exactly about your case regarding this concern?

    If Celiac disease is real, if it's hard to diagnose, if it really can kill people and make them live hard lives before that, if it's still under a heavy train of research and investigation, why can't you just let it go and admit maybe you spoke too soon of something else (namely the phenomenon of the industry taking this market, which is a totally different story of the people finding themselves intolerant without any reliable simple test medically available) for the bad reason you thought it could bring you some more of this popularity juice you seem to be after (or so may we conclude with some evidence)?

    Or do you believe it's all a false thing with many proofs of it and studies to debunk the fact like this blood-type diet? And then what are these studies, those data, where do you find to infer the gluten-free diet benefits are unreal for those who follow it? Can't you see the series of contradictions in your cues? We all can see them right through though...

    To the readers of this blog, the issue with the Celiac thing, Hank Campbell, becomes all yours in a sort of pitiful confusion
    I have never once criticized people with celiac disease, so I am not sure why I got invoked in your comment. This piece does not mention celiacs either, though it does say
    the martini diet, the tapeworm diet and going gluten-free
    which are all fad diets. Or are you claiming that the 20%+ of people buying gluten-free are actually celiacs? Because you have overturned all of immunology if you can back that up.
    Hi 'anonymous', if that is your real name,

    It seems that you, like many others have jumped on the bandwagon of gluten free diets. Note, I say gluten free diets and NOT coeliac disease. In no sentence did Katherine make mention of coeliac disease, yet that is what you are taking about, as if they were the same thing.

    No one is questioning the veracity of coeliac disease. It is very serious but very uncommon, affecting 0.05% of the population. You are wrong in saying it is difficult to diagnose, it's very easy to diagnose. There is a screening blood test, for anti gliadin antibodies and is diagnosed on colonoscopy and biopsy. Easy.

    Having a gluten free, or even more ridiculously, a low gluten diet is not harmful. To you. What you are doing, however, is wasting a lot of money and adding to the confusion of the population who now perceive gluten free diets to be a fad, which they are for a majority of people who eat them. You increase the risk that people In the food service industry become jaded and dismissive of those who request a gluten free desert when they didn't care about the presence barley in their soup, or were happy to have a beer with their meal. This is not an unreasonable reaction when those who are 'gluten free' because they self-diagnosed an 'intolerance' outnumber true coeliacs 100:1.

    Coeliac disease is a serious autoimmune disorder for which the treatment is a gluten free diet. The issue for these people is that even trace amounts of gluten, while they may not cause symptoms, significantly increase their risk if bowel cancer. If you believe you are a coeliac, I thoroughly recommend you get tested. In the interim leave professionals who know the difference between a fad diet which happens to correspond to the treatment of a serious disease alone.

    Kind regards,