Nutrition
If your blood group holds the key to your optimum diet, it might just be a happy coincidence.
Your blood group may hold the key to your optimum diet.
Question:
My friend follows the blood-type diet. She has blood type O and eats meat, a limited amount of dairy foods and wheat for better health. She believes many others might bene t from this diet. Is there any real science behind it, or is it just a fad?
Answer:
There is no one alive who is youer than you, wrote Dr Seuss. Indeed, you are genetically unique, so should your diet be unique, too? US naturopath Peter D’Adamo is among those who has offered an answer to that question. He asserted that, because our blood group is associated with the risk of certain health conditions, we should tailor our eating to our blood type.
In his 1996 book Eat Right for Your Type, D’Adamo outlined diets for each of the four blood types with the aim of improving health and reducing the risk of chronic diseases.
D’Adamo’s theory is that those with blood type O would thrive on a diet that resembles the meaty high-protein fare typical of certain groups in the hunter-gatherer era. Type O is considered the ancestral blood type in humans. Those with blood type A would thrive on a vegetarian diet, as this blood type is said to have evolved when humans began cultivating land. Blood type B originated in nomadic tribes, he says, so they would benefit from dairy products. Finally, blood type AB is lumped with a diet midway between that of type A and type B.
Some of D’Adamo’s nutritional recommendations, irrespective of blood type, fit with current nutrition advice, such as advising those with type A to “limit sugar, caffeine and alcohol”.
What’s more, there is substantial evidence that blood type is linked to disease risk. For example, those with type O have a reduced risk of deep vein thrombosis, and type B individuals have a lower risk of type 2 diabetes compared to type O.
In 2010, Scandinavian researchers noted that those with type A had an increased risk of gastric cancer, while peptic ulcer risk was highest among those with type O.
In 2017, a Shanghai cohort study following over 18,000 Chinese men found that people with type B had a statistically lower risk of all cancers than those with type A. This suggests that genetic traits linked to our blood type may play a role in the development of cancers in the gastrointestinal and urinary tracts.
Interestingly, in 2012, researchers noted that blood type seems to modulate the composition of our all-important gut microbiota. T o get to the bottom of whether the blood-type diet uniquely benefits our health, researchers at the University of Toronto analysed data from 1455 participants in the Toronto nutrigenomics and health study. The researchers assessed dietary intake and used a diet score to calculate the similarity of the participants’ diets to each of the four blood-type diets proposed by D’Adamo.