By CASEY CARR
In the late 90s, Dr. Peter J. D’Adamo made a tsunami wave in the diet world. His 1996 book Eat Right 4 Your Type has sold over seven million copies and has been translated into 60 different languages. Not a diet book, but a “Complete Blood Type Encyclopedia,” this hefty read discusses the connection between blood type and disease, conditions, vitamins, supplements, herbs, food, sleep, stress reduction exercise … you name it, and Dr. D’Adamo has included it in his thorough encyclopedia.
D’Adamo claims that current disease states, along with all the above aforementioned conditions, are a product of our ancestral foundation. The ABO blood typing system has evolved over thousands of years from genetic mutation, and has enabled scientists and anthropologists to better understand the movement and grouping of our primordial relatives. Based on blood type A, B, AB or O, it gives insight into how our ancestors adapted to changing climates, mutating germs and food supplies. According to D’Adamo’s encyclopedia, blood group O is marked by the rise of humans to the top of the food chain, blood group A developed during the agricultural revolution and blood groups B and AB arose from the migration of people from Africa to Europe and Asia. According to D’Adamo each ABO blood type processes food differently, and following a diet that is specific to an individual’s blood type can aid in improving health, energy and reducing risk of the development of certain diseases.
Sounds compelling, right? It’s basically a form of personalized nutrition based on genetics that an individual can easily apply by just knowing what one’s blood type is. No wonder this blood type encyclopedia has had a strong following for over a decade. However, the strength of D’Adamo’s extensive scientific conclusions remains in question. A recent systematic review conducted by Cusak, et. al determined that there is no evidence regarding the validity of blood type diets. No scientific studies have been conducted to examine specific health effects of a diet based on blood type.
In addition to lacking scientific validity, D’Adamo’s encyclopedia is overwhelming and difficult to apply. The 600-plus-page compendium is comprehensive, but it does not relate any utility in applying his theory. Though it specifies which fish — seriously, every type of fish (a list of 83 to be exact) — are ones to “avoid,” are “beneficial” or are “neutral” based on blood type, it is overwhelming to the average consumer as to how to apply these rough guidelines to everyday meals. That’s where D’Adamo’s cookbook, Eat Right 4 Your Type Personalized Cookbook, comes into the marketing scheme. Not to mention his latest book, The GenoType Diet, which profiles individuals as one of six genotypes based on simple anatomical measurements and blood type. D’Adamo continues to evolve his diet theory, and yet there is no scientific research to back it up.
It boils down to the simple fact that the role of genetics is complex, and doctors and scientists are continually trying to figure out the links between disease and DNA. Though blood type is certainly one aspect of our genetic makeup, the genetic code reaches far beyond ABO blood typing. I will not pretend to be an expert in the field of genetics, but one thing I can conclude from college biology is that health status is a complex interaction of genetics and environmental factors. D’Adamo’s attempt to keep up with the evolving field of personalized medicine takes an interesting approach, but the lack of scientific evidence and the complexity of the genome makes it only an interesting theory.