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The Deconstructed Dish: What’s the Hype about Blood Type?

By Jenn Randazzo, MS RD on June 15, 2015, categorized in Plant-based Nutrition

The Deconstructed Dish: What’s the Hype about Blood Type?

Who has time to stay savvy about latest nutrition research these days? Besides, a nutritional breakthrough or wonder food makes headlines every Monday only to be disproved by Tuesday, right?  Even though you may be seconds away from tossing in the kitchen towel and just eating your favorite comfort foods because you’re so frustrated and confused, don’t yet.

Nutrition trends come and go, but I’m here to provide you with evidence-based, sustainable ways to improve your health.  Each month, I’ll focus on a nutritional hot topic, sift through tons of research, separate fact from fiction, and provide realistic solutions to help you improve your life.

About four years ago, I went to Barnes & Noble and despite my best intentions to look for a non-culinary or health-related book, I, as if in a hypotonic trance, wandered over to the ginormous display of New Arrivals in the Diet and Nutrition section. After panning the wall for a few moments, a book titled Eat Right 4 Your Blood Type caught my curious eye.

According to the author, Peter D’Adamo, each blood type (A, B, AB and O) requires a unique set of foods for optimal health. Conversely, each type should also avoid a specific set of foods as well. This concept suggests that different blood types process foods differently.  For instance, Type Os benefit from high animal-based proteins, while Type As thrive on a vegetarian diet.  Type Bs should avoid corn and lentils while Type ABs should stay away from red meat and kidney beans.

Sifting through the research

Despite D’Adamo’s book being a New York Times best-seller, there is no evidence to support the concept that each blood type has unique dietary needs.

Last year, the University of Toronto conducted a large, well-executed study that “found no evidence to support the ‘blood-type’ diet theory.”Wang J. et al. (2014). ABO Genotype, ‘Blood-Type’ Diet and Cardiometabolic Risk Factors.  PLOSone. Accessed on January 5, 2015 from: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0084749#references.Participants (n=1455) completed a 196-question food frequency questionnaire that described their current eating patterns. These questionnaires were then scored and filed into one of four “Blood Type Diets.”  Researchers then compared the questionnaires from each Blood Type Diet to the actual blood types of the participants. While the results found that the Blood Type Diets are associated with favorable effects on some cardiovascular and metabolic risk factors (likely due to the fact that this diet advocates high fruit and vegetable content), they did not find any significant correlation between the Blood Type Diet philosophy and actual blood types.

This wasn’t the first to debunk this philosophy as well.  In 2013, a systematic review published in The American Journal of Clinical Nutrition found the Blood Type Diet lacked sufficient evidence after researchers evaluated 1415 published studies that presented data on blood type diets.Cusack L. (2013). Blood type diets lack supporting evidence: a systematic review. American Journal of Clinical Nutrition. 98(1): 99-104.  Accessed on January 5, 2015 from: http://ajcn.nutrition.org/content/early/2013/05/22/ajcn.113.058693.full.pdf+html.

My Suggestion:

I don’t personally subscribe to or endorse the Blood Type Diet philosophy, but I am passionate about encouraging people to listen to their bodies. Tune in and hear what your body is saying to you. If you’re tired, sore, unable to manage your weight, and/or moody, your body could by trying to tell you that it’s imbalanced in some way.

To support rebalancing your body:

  • Stay away from fad diets and quick fixes
  • Get sufficient restPatel S. (2008). Short sleep duration and weight gain: a systematic review. Obesity. 16(3): 643 – 653. Accessed on January 8, 2015 from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2723045/. (Personally, I crave 8 -10 hours).
  • Try different foods, exercises and meditations to see what makes you physically and emotionally feel better

Your body and mind have a voice, so just be willing to lend an empathetic ear. If you are looking to improve your health, I wouldn’t recommend seeking advice from the Blood Type Diet as your first move. Instead, do what we know to be healthful.  Eat plant-based, move your body in a way that feels good as much as you can, and embrace mindfulness on a daily basis.

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