What Is The Blood Type Diet?

Is the blood type diet right for you? Learn the facts here so you can make an informed decision.

A young woman adapting a blood type diet with a healthy meal consisting of salmon and tomatoes

Have you ever heard of the blood type diet? This diet was the subject of the best-selling book “Eat Right 4 Your Type” by Dr. Peter J D’Adamo. In the book, D’Adamo explains how he thinks your blood type affects your body chemistry and determines which foods you should be eating. D’Adamo reported that his patients who went on this diet reported improved weight loss, better digestive function, more energy, and improved mental clarity.

But are any of these findings substantiated by science? No. So far, no major studies have been able to pinpoint any evidence that the blood type diet can help with any of the issues D’Adamo claims it addresses. In fact, the diet has been debunked by a study that says everyone — not just people with certain blood types — benefits from a plant-based diet.

So, why does the popularity of the blood type diet persist? Is there anything we can learn from it? Keep reading to learn more about this controversial way of eating.

What Is The Blood Type Diet? 

The blood type diet is based on the evolution of the four blood types: A, AB, B, and O. Genetic markers tell us when each blood type arose, and what ancient people with those blood types ate. For example, the first ancient people with blood type A were farmers and therefore evolved to eat the grains they grew.

In “Eat Right 4 Your Type,” D’Adamo says that you may be more susceptible to different health conditions based on your blood type. For example, he claims that people with O blood type are more prone to allergies and hay fever.

There is no scientific evidence to back up these claims, but that doesn’t mean that all of the advice in the book is unhelpful. D’Adamo recommends that people of all blood types eat more whole foods and cut out processed foods. Most experts agree that this sensible, science-based nutritional advice is the key to good health. TCM Physician Lim Sock Ling agrees. Physician Lim stresses the importance of eating well because “blood originates from food essence, which is derived from digested food.”

She describes the main functions of blood:

  • To provide nutrients for organs, tissues and meridians
  • To nourish the skin, bones, and muscles
  • Maintain healthy body movement and sensation

A poor diet can result in symptoms like dizziness, vertigo, ringing in the ears (tinnitus), or limb weakness. It can also result in slower thinking, memory issues, and insomnia.

Type A

A woman with red curly hair arranging a plate of cooked vegetarian salad for dinner
According to the blood type diet, a vegetarian diet is best for people with blood type A.

People with blood type A are descended from ancient people who were farmers. D’Adamo says type As can digest carbohydrates better than other blood types and do well on a meat-free diet. For best health, he suggests you eat a diet rich in fresh fruits and vegetables, beans and legumes, and whole grains. D’Adamo says people with type A blood have a sensitive immune system and should choose organic foods when possible.

Type AB

People with blood type AB can enjoy a wider variety of foods for both types A and B, according to D’Adamo. Tofu, seafood, dairy, and green vegetables are all recommended. Limit foods like red meat, beans, corn, and smoked or cured meats. People with type AB blood tend to have low stomach acid.

Type B

People with type B blood are thought to have descended from nomads and therefore equipped to eat a variety of foods, according to D’Adamo’s analysis. He suggests you eat a diet full of fresh fruits, vegetables, and meats. The main foods to avoid are corn, wheat, buckwheat, lentils, tomatoes, peanuts and sesame seeds, and chicken.

Type O 

A man eating cooked well done steak with mustard sauce for lunch
Red meat is a recommended dietary choice for people with blood type O.

Type O is the first known blood type, and people with it have ancestral ties to hunter-gatherers, says Dr. D’Adamo. The O blood type diet is close to the paleo diet, filled with lean meats, poultry, fish, and vegetables. Avoid high-carbohydrate foods like grains, beans, and corn. You can eat dairy in moderation.

Why The Blood Type Diet Is Thought To Work  

Why do we have different blood types? And why would blood type have an impact on how food affects us? Blood types are thought to be related to our immune system and help ward off diseases. By eating foods we are genetically equipped to eat, we can avoid inflammation that is thought to be the cause of many diseases. The diet claims to offer an easy way to identify the foods that are best for your unique biochemical makeup.

Does The Blood Type Diet Really Work?

Most experts do not recommend this diet. That doesn’t mean that there is nothing we can learn from the blood type diet. One major takeaway is that there is no one-size-fits-all way to eat.

This isn’t a new way of thinking. This individualized way of thinking about health is basic to Traditional Chinese Medicine (TCM). In TCM, practitioners evaluate their patients in a holistic manner and treat the body as a whole. While TCM and the blood type diet aren’t the same, their approach to eating is very similar. Physician Lim recommends a specifically-tailored diet to each of her patients. And she uses a patient’s current body constitution, lifestyle, and external factors to help her determine that regimen.

If you’re still curious about the blood type diet, here are some pros and cons to help you decide if it’s right for you.

Pros

The general advice the diet offers for most people — eating more whole foods and more leafy greens and reducing consumption of processed foods — is universally healthy.

Nutritious whole foods arranged in a flat lay on top of a kitchen counter.
The blood type diet recommends eating more whole foods, vegetables, and fruits.

Cons

The various “type” diets are too restrictive. Not only is a restrictive diet difficult to maintain, but you may also become deficient in certain vitamins and minerals because of the limited number of foods you can eat. If you need help with weight loss, digestion, or energy, adding a supplement to your diet may be more effective.

Whether or not you want to try the blood type diet is up to you. Just keep in mind that no scientific studies have found that determining what you should eat based on your blood type is effective. Fad diets will come and go, but a balanced diet filled with whole foods and lots of fresh fruits and vegetables will always be medically sound. Share this article with your friends and family who struggle with finding the right diet. It’s may also be beneficial to take an immune-boosting supplement to further protect against diseases.

References

  1. Harvard Health Blog. 2019. Diet not working? Maybe it’s not your type. [Accessed 28 December 2021]
  2. American Red Cross. N.d. Facts About Blood and Blood Types. [Accessed 28 December 2021]
  3. Eat Right 4 Your Type. 2019. Blood Type and Your Health. [Accessed 28 December 2021]
  4. Physicians Committee For Responsible Medicine. 2020. New Study Debunks Blood Type Diet. [Accessed 31 January 2022]
  5. T. Colin Campbell Center For Nutrition Studies. 2019. The Blood Type Diet: Science or Fiction? [Accessed 31 January 2022]
  6. NCBI. 2013. Blood type diets lack supporting evidence: a systematic review. [Accessed 31 January 2022]

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