Table of ContentsView AllTable of ContentsBlood Type Diet TheoryProposed BenefitsConsiderationsDietary Restrictions
Table of ContentsView All
View All
Table of Contents
Blood Type Diet Theory
Proposed Benefits
Considerations
Dietary Restrictions
Blood type diet theory proposes that those with group A blood should eat a mostly vegetarian diet, those with group O should focus on high animal protein, and those with group B should eat dairy products. It recommends a diet that has elements of both the A and B diet for people with AB blood.
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How Is the Blood Type Diet Claimed to Work?
The blood type diet proposes that because of evolutionary history, blood type can affect how certain foods are digested. By extension, eating accordingly could provide health benefits.
The theory is that type O was the original “ancestral” blood type, meaning the blood type of the earliest humans. Based on the diets of early humans as hunter-gatherers, the diet claims people with this blood type are best suited to eating animal protein.
Theoretically, group A blood evolved when humans began to farm and consume a more vegetarian diet, and group B blood was developed among nomadic tribes who had a high consumption of dairy. The AB type formed through reproduction between people with type A and type B blood.
However, there is evidence that the first humans had blood types in addition to type O. Their close relatives (including Neanderthals) have types A, B, and O.In primates, types A and O are seen in chimpanzees, A and B in gorillas, and A, B, and AB in orangutans and gibbons.
Blood Types and Health
Older research from the 1950s and 1960s compared blood types for the risk ofischemicheart disease (coronary artery disease). People with type O blood had a modest reduction in risk compared to those with other blood types.
A 2016 meta-analysis of case-control and cohort studies found evidence that supported these earlier studies, with findings suggesting a 15% reduced risk of coronary artery disease (CAD) for blood group O.
Other studies have suggested that people with type A blood have an increased risk of higher total cholesterol and low-densitylipoprotein(LDL) cholesterol (considered bad cholesterol) concentrations.Studies have found inconsistent relationships between blood types and the risk oftype 2 diabetes.
These findings have prompted questions about whether a person could benefit from dietary choices tailored to their blood type. There is a lack of research on this subject, and the limited amount of observational data does not support the health benefits of eating based on blood type.
Blood Type O Foods
According to the blood type diet theory, those with type O blood should eat:
They should limit:
For weight loss, they should avoid:
Blood Type A Foods
The blood type diet theorizes that people with type A blood should eat:
They should avoidred meat.
Blood Type B Foods
Blood Type AB Foods
Blood type diet theorizes that people with type AB blood should eat:
Proposed Benefits of Eating Based on Your Blood Type
Studies examining the blood type diet found that the dietary suggestions for type A (increased intake of fruits, vegetables, andgrains) did benefit those with type A blood, but they also benefited those with types O, B, and AB.
Similarly, the diet proposed for group AB, which advises limiting butter and eating eggs and fish as the main animal proteins, is associated with a more favorable cardiometabolic profile (tests for heart health and blood sugar management) than the type B plan, which has fewer restrictions on many animal products. These results applied to people of all blood types.
What Does the Research Say?There is a lack of high-quality studies published in peer-reviewed medical literature on the blood type diet.The main findings of existing studies examining the influence of blood type on diet and health benefits include:Health outcomes from the foods recommended for each blood type are related to the foods eaten, not the blood type, and are not unique to any blood type.Regardless of blood type, those whose eating patterns are similar to those outlined for the type A blood group (more fruit, vegetables, and grain, less meat) tend to have better cardio-metabolic (cardiovascular and metabolic) outcomes, such as lowerbody mass index (BMI), waist circumference, serum cholesterol and triglyceride levels (fats in the blood), andinsulin resistance(when cells in the body don’t respond well to the hormone insulin and have difficulty taking up glucose from the blood, requiring more insulin).The type O diet recommendations (emphasizing meat, fruits, and vegetables and limiting grains) have been associated with lower triglyceride levels, regardless of the person’s blood type.Evidence does not support using blood type as a basis for determining what foods to eat or avoid.
What Does the Research Say?
There is a lack of high-quality studies published in peer-reviewed medical literature on the blood type diet.The main findings of existing studies examining the influence of blood type on diet and health benefits include:Health outcomes from the foods recommended for each blood type are related to the foods eaten, not the blood type, and are not unique to any blood type.Regardless of blood type, those whose eating patterns are similar to those outlined for the type A blood group (more fruit, vegetables, and grain, less meat) tend to have better cardio-metabolic (cardiovascular and metabolic) outcomes, such as lowerbody mass index (BMI), waist circumference, serum cholesterol and triglyceride levels (fats in the blood), andinsulin resistance(when cells in the body don’t respond well to the hormone insulin and have difficulty taking up glucose from the blood, requiring more insulin).The type O diet recommendations (emphasizing meat, fruits, and vegetables and limiting grains) have been associated with lower triglyceride levels, regardless of the person’s blood type.Evidence does not support using blood type as a basis for determining what foods to eat or avoid.
There is a lack of high-quality studies published in peer-reviewed medical literature on the blood type diet.
The main findings of existing studies examining the influence of blood type on diet and health benefits include:
Talking to a registered dietitian can help you find evidence-based eating plans that fit your goals and lifestyle.
Summary
The blood type diet is based on a book that proposes eating foods tailored to your blood type could have health benefits, such as a mostlyvegetariandiet for type A and an emphasis on animal protein for type O.
There is no quality evidence that blood type impacts dietary choices or that there is a benefit to choosing an eating plan based on blood group.
Any health benefits from eating according to the suggestions for each blood type apply to anyone who follows them regardless of blood type.
Instead of following a diet based on your blood type, it is advisable to choose evidence-based eating plans that address your health concerns, such as theDASH dietand/or talking to a registered dietitian.
11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Harvard Health.Diet not working? Maybe its not your type.Wang J, García-Bailo B, Nielsen DE, El-Sohemy A.ABO genotype, ‘blood-type’ diet and cardiometabolic risk factors. Ashton N, ed.PLoS ONE. 2014;9(1):e84749. doi:10.1371/journal.pone.0084749American National Red Cross.Facts about blood and blood types.Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, Chiaroni J.Blood groups of Neandertals and Denisova decrypted.PLoS One. 2021;16(7):e0254175. doi:10.1371/journal.pone.0254175Farhud DD, Zarif Yeganeh M.A brief history of human blood groups.Iran J Public Health. 2013;42(1):1-6.Barnard ND, Rembert E, Freeman A, Bradshaw M, Holubkov R, Kahleova H.Blood type is not associated with changes in cardiometabolic outcomes in response to a plant-based dietary intervention.Journal of the Academy of Nutrition and Dietetics. 2021;121(6):1080-1086. doi:10.1016/j.jand.2020.08.079Chen Z, Yang SH, Xu H, Li JJ.ABO blood group system and the coronary artery disease: an updated systematic review and meta-analysis.Sci Rep. 2016;6:23250. doi:10.1038/srep23250Etemadi A, Kamangar F, Islami F, et al.Mortality and cancer in relation to ABO blood group phenotypes in the Golestan Cohort Study.BMC Med. 2015;13:8. doi:10.1186/s12916-014-0237-8Lemaitre M, Passet M, Ghesquière L, Martin C, Drumez E, Subtil D, Vambergue A.Is the development of gestational diabetes associated with the ABO blood group/Rhesus phenotype?Front Endocrinol (Lausanne). 2022;13:916903. doi:10.3389/fendo.2022.916903Cusack L, De Buck E, Compernolle V, Vandekerckhove P.Blood type diets lack supporting evidence: a systematic review.The American Journal of Clinical Nutrition. 2013;98(1):99-104. doi:10.3945/ajcn.113.058693Ohio State University Wexner Medical Center.Should you try the ‘blood type diet’?
11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Harvard Health.Diet not working? Maybe its not your type.Wang J, García-Bailo B, Nielsen DE, El-Sohemy A.ABO genotype, ‘blood-type’ diet and cardiometabolic risk factors. Ashton N, ed.PLoS ONE. 2014;9(1):e84749. doi:10.1371/journal.pone.0084749American National Red Cross.Facts about blood and blood types.Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, Chiaroni J.Blood groups of Neandertals and Denisova decrypted.PLoS One. 2021;16(7):e0254175. doi:10.1371/journal.pone.0254175Farhud DD, Zarif Yeganeh M.A brief history of human blood groups.Iran J Public Health. 2013;42(1):1-6.Barnard ND, Rembert E, Freeman A, Bradshaw M, Holubkov R, Kahleova H.Blood type is not associated with changes in cardiometabolic outcomes in response to a plant-based dietary intervention.Journal of the Academy of Nutrition and Dietetics. 2021;121(6):1080-1086. doi:10.1016/j.jand.2020.08.079Chen Z, Yang SH, Xu H, Li JJ.ABO blood group system and the coronary artery disease: an updated systematic review and meta-analysis.Sci Rep. 2016;6:23250. doi:10.1038/srep23250Etemadi A, Kamangar F, Islami F, et al.Mortality and cancer in relation to ABO blood group phenotypes in the Golestan Cohort Study.BMC Med. 2015;13:8. doi:10.1186/s12916-014-0237-8Lemaitre M, Passet M, Ghesquière L, Martin C, Drumez E, Subtil D, Vambergue A.Is the development of gestational diabetes associated with the ABO blood group/Rhesus phenotype?Front Endocrinol (Lausanne). 2022;13:916903. doi:10.3389/fendo.2022.916903Cusack L, De Buck E, Compernolle V, Vandekerckhove P.Blood type diets lack supporting evidence: a systematic review.The American Journal of Clinical Nutrition. 2013;98(1):99-104. doi:10.3945/ajcn.113.058693Ohio State University Wexner Medical Center.Should you try the ‘blood type diet’?
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Harvard Health.Diet not working? Maybe its not your type.Wang J, García-Bailo B, Nielsen DE, El-Sohemy A.ABO genotype, ‘blood-type’ diet and cardiometabolic risk factors. Ashton N, ed.PLoS ONE. 2014;9(1):e84749. doi:10.1371/journal.pone.0084749American National Red Cross.Facts about blood and blood types.Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, Chiaroni J.Blood groups of Neandertals and Denisova decrypted.PLoS One. 2021;16(7):e0254175. doi:10.1371/journal.pone.0254175Farhud DD, Zarif Yeganeh M.A brief history of human blood groups.Iran J Public Health. 2013;42(1):1-6.Barnard ND, Rembert E, Freeman A, Bradshaw M, Holubkov R, Kahleova H.Blood type is not associated with changes in cardiometabolic outcomes in response to a plant-based dietary intervention.Journal of the Academy of Nutrition and Dietetics. 2021;121(6):1080-1086. doi:10.1016/j.jand.2020.08.079Chen Z, Yang SH, Xu H, Li JJ.ABO blood group system and the coronary artery disease: an updated systematic review and meta-analysis.Sci Rep. 2016;6:23250. doi:10.1038/srep23250Etemadi A, Kamangar F, Islami F, et al.Mortality and cancer in relation to ABO blood group phenotypes in the Golestan Cohort Study.BMC Med. 2015;13:8. doi:10.1186/s12916-014-0237-8Lemaitre M, Passet M, Ghesquière L, Martin C, Drumez E, Subtil D, Vambergue A.Is the development of gestational diabetes associated with the ABO blood group/Rhesus phenotype?Front Endocrinol (Lausanne). 2022;13:916903. doi:10.3389/fendo.2022.916903Cusack L, De Buck E, Compernolle V, Vandekerckhove P.Blood type diets lack supporting evidence: a systematic review.The American Journal of Clinical Nutrition. 2013;98(1):99-104. doi:10.3945/ajcn.113.058693Ohio State University Wexner Medical Center.Should you try the ‘blood type diet’?
Harvard Health.Diet not working? Maybe its not your type.
Wang J, García-Bailo B, Nielsen DE, El-Sohemy A.ABO genotype, ‘blood-type’ diet and cardiometabolic risk factors. Ashton N, ed.PLoS ONE. 2014;9(1):e84749. doi:10.1371/journal.pone.0084749
American National Red Cross.Facts about blood and blood types.
Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, Chiaroni J.Blood groups of Neandertals and Denisova decrypted.PLoS One. 2021;16(7):e0254175. doi:10.1371/journal.pone.0254175
Farhud DD, Zarif Yeganeh M.A brief history of human blood groups.Iran J Public Health. 2013;42(1):1-6.
Barnard ND, Rembert E, Freeman A, Bradshaw M, Holubkov R, Kahleova H.Blood type is not associated with changes in cardiometabolic outcomes in response to a plant-based dietary intervention.Journal of the Academy of Nutrition and Dietetics. 2021;121(6):1080-1086. doi:10.1016/j.jand.2020.08.079
Chen Z, Yang SH, Xu H, Li JJ.ABO blood group system and the coronary artery disease: an updated systematic review and meta-analysis.Sci Rep. 2016;6:23250. doi:10.1038/srep23250
Etemadi A, Kamangar F, Islami F, et al.Mortality and cancer in relation to ABO blood group phenotypes in the Golestan Cohort Study.BMC Med. 2015;13:8. doi:10.1186/s12916-014-0237-8
Lemaitre M, Passet M, Ghesquière L, Martin C, Drumez E, Subtil D, Vambergue A.Is the development of gestational diabetes associated with the ABO blood group/Rhesus phenotype?Front Endocrinol (Lausanne). 2022;13:916903. doi:10.3389/fendo.2022.916903
Cusack L, De Buck E, Compernolle V, Vandekerckhove P.Blood type diets lack supporting evidence: a systematic review.The American Journal of Clinical Nutrition. 2013;98(1):99-104. doi:10.3945/ajcn.113.058693
Ohio State University Wexner Medical Center.Should you try the ‘blood type diet’?
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