Is there any science behind the blood type diet?

Dr. D’Adamo is famously known for his ‘Eat Right for your Type’ diet. Could there be any truth to this great claim and why do many people report it to be the perfect diet?

This was one of our research assignments and has got me thinking how important it is that people make the right choice when it comes to following a generic diet plan.

“Blood type O have a lower risk for heart disease, but a higher risk for developing stomach ulcers. People who are blood type A have higher risks of microbial infections, but Type A women experience a higher rate of fertility. Other research has found that people with type AB and B blood have a much higher risk of developing pancreatic cancer.”

D’Adamo based his work on the four blood groups all reacting to different food types. It wasn’t the food itself but rather one type of protein, Lectin, that the foods contained. He also focuses on the origin of mankind with the O type being the earliest, followed by the A type then the B type and lastly the most recent and rarest the AB blood type. He linked this progression of blood type to the food sources that were available to mankind at that time.

Where D’Adamo has gathered some steam is by linking certain diseases with certain blood types. These claims are supported by clinical evidence. There are several articles and forms of literature that can be found linking such points. Where D’Adamo’s theory starts fumbling is by not providing any evidence to support the link between certain blood types and diet. In addition to this there is little evidence to show that lectins cause the amount of damage he describes.

“I can eat more now than I’ve ever eaten and I still can’t put on a pound. I do miss a good Indian curry, but if you are going to try to enhance your diet, it will mean giving up something you love to eat,” Sir Cliff Richard

Perhaps his avid supporters are not concerned about the science behind the diet and in context the four diets have considerable benefits compared to the western diet. This is one of the very reason people believe in it. Most people would feel better swapping out a highly processed and sugar fuelled diet for a more balanced diet that includes fresh fruit, meat and dairy. Noticeable weight loss is one of the most favourable outcomes and as we are aware weight loss is always going to be a winner.

So my question is would I recommend this diet in clinic? In short, no. Firstly as we are unique individuals so should our diets be unique to us. Secondly the evidence doesn’t back the claims and I can’t recommend a diet that tells a person to avoid cabbage, avocados and oranges but encourages wine and coffee. As appealing as that may be, we know that when somethings sounds to good to be true it normally is.

References: Aird, I., Bentall, H. and Roberts, J. (1953). Relationship Between Cancer of Stomach and the ABO Blood Groups. BMJ, 1(4814), (2019). “The Zone” and “Blood-Type” Diet Fads: An Vegan Health Article. [online] Available at: [Accessed 9 May 2019].Cusack, L., De Buck, E., Compernolle, V. and Vandekerckhove, P. (2013). Blood type diets lack supporting evidence: a systematic review. The American Journal of Clinical Nutrition, 98(1), pp.99-104.D’Adamo, P. and Whitney, C. (2001). Eat right 4 your type. London: Century, pp.27, 57, (2019). The official Blood Type Diet website. [online] Available at: [Accessed 9 May 2019].Edgren, G., Hjalgrim, H., Rostgaard, K., Norda, R., Wikman, A., Melbye, M. and Nyren, O. (2010). Risk of Gastric Cancer and Peptic Ulcers in Relation to ABO Blood Type: A Cohort Study. American Journal of Epidemiology, 172(11), pp.1280-1285.Edgren, G., Hjalgrim, H., Rostgaard, K., Norda, R., Wikman, A., Melbye, M. and Nyren, O. (2010). Risk of Gastric Cancer and Peptic Ulcers in Relation to ABO Blood Type: A Cohort Study. American Journal of Epidemiology, 172(11), pp.1280-1285.Fagherazzi, G., Gusto, G., Clavel-Chapelon, F., Balkau, B. and Bonnet, F. (2014). ABO and Rhesus blood groups and risk of type 2 diabetes: evidence from the large E3N cohort study. Diabetologia, 58(3), pp.519-522.Gastric ulcers, blood groups, and acid secretion. (1964). Gut, 5(6), pp.610-610.Healthline. (2019). The Blood Type Diet: An Evidence-Based Review. [online] Available at: [Accessed 9 May 2019].The Sydney Morning Herald. (2019). Grading the blood type diet. [online] Available at: [Accessed 17 May 2019].Wang, J., García-Bailo, B., Nielsen, D. and El-Sohemy, A. (2014). ABO Genotype, ‘Blood-Type’ Diet and Cardiometabolic Risk Factors. PLoS ONE, 9(1), p.e84749.Zakai, N., Judd, S., Alexander, K., McClure, L., Kissela, B., Howard, G. and Cushman, M. (2014). ABO blood type and stroke risk: the REasons for Geographic And Racial Differences in Stroke Study. Journal of Thrombosis and Haemostasis, 12(4), pp.564-570.

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