The Blood Type Diet: Does It Work?

Proponents claim that the blood type diet can improve digestion, energy levels, and disease prevention. It suggests that blood type influences how the body reacts to food. However, scientific evidence supporting these claims is lacking.

Learn about the principles of the blood type diet and what research says about it.

Blood type A diet

About 42% of Americans have blood type A.

People with blood type A are encouraged to follow a primarily vegetarian, plant-based diet. This is because they have sensitive immune systems and are at higher risk of diabetes, cardiovascular disease, and cancer.

Blood type A benefits from carbs for overall health. With lower levels of hydrochloric acid, intestinal alkaline phosphatase, and higher levels of intestinal disaccharide digestive enzymes, carbs are more effectively digested and metabolized compared to animal protein and fat.

• Foods to eat with blood type A:

• Organic, fresh fruits (apples, berries, peaches)
• Vegetables
• Legumes
• Tofu
• Whole grains
• Nuts and seeds
• Limit beans, turkey, seafood, and dairy due to insulin reactions

Blood type B diet

About 10% of Americans have blood type B.

People with blood type B are adaptable and can obtain nutrients from both animals and vegetables. However, maintaining balance is critical. People with this blood type tend to be physically and psychologically more fit than those with other blood types.

A diet rich in vegetables, meat, and limited dairy is recommended for blood type B. Their strong immune system and tolerant digestive system allow them to better withstand chronic illnesses compared to other blood types.

• Foods to eat with blood type B:

• Green vegetables
• Fruits
• Eggs
• Low-fat dairy
• Meat (except chicken and pork)
• Legumes
• Grains

Blood type AB diet

Only about 4% of Americans have blood type AB, which is associated with a higher risk of stomach cancer.

People with blood type AB have low stomach acid levels and should consume smaller, more frequent meals. Avoiding carb and protein combination benefits digestion and metabolism.

Recommended foods for blood type AB include tofu, seafood, dairy, and green vegetables.

• Foods to eat with blood type AB:

• Seafood and lamb
• Tofu
• Fruits
• Eggs
• Dairy
• Grains
• Seeds and nuts

Blood type O diet

About 44% of Americans have blood type O.

Blood type O is considered the "original" type, associated with hunter-gatherers. The recommended diet is similar to the paleo diet, high in protein and gluten-free.

Blood type O has high stomach acid levels, making it more efficient in digesting protein, fat, and absorbing calcium.

• Foods to eat with blood type O:

• Lean meat, fish, and chicken
• Fruits
• Vegetables
• Limit grains, beans, eggs, legumes, and dairy

The role of lectin in the blood type diet

Lectin is a protein found in grains, nuts, seeds, and legumes. It binds sugar molecules and some theories suggest it can interfere with digestion and nutrient absorption, as well as agglutinate blood cells.

Claims

Some nutritionists believe that consuming lectins causes blood cells to clump together, leading to hormonal disruptions.

They claim that different blood types react differently to specific foods and their lectins. Incompatible lectins may target certain organs or bodily systems, agglutinating blood cells in those areas. The blood type diet aims to address these factors.

Facts

There is no evidence supporting the idea that lectins affect people differently based solely on their blood type. Research has shown that lectins do not cause blood clumping as claimed.

Lectins are present in about 30% of our diet and many of these are nutritious plant-based foods rich in antioxidants, fiber, vitamins, and minerals. Eliminating an entire group of healthy foods based on theory rather than evidence is unnecessary.

Most lectins in the average diet are cooked off before consumption, making them harmless. The immune system also removes 95% of consumed lectins.

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Potential benefits of the blood type diet

Each subtype of the blood type diet promotes a low intake of processed foods and added sugars, focusing on lean meat, fruits, and vegetables, which are beneficial for overall health. This approach can help reduce inflammation and lower the risk of disease.

While the overall diet lacks strong scientific evidence, certain aspects, such as plant-based foods, have been shown to support healthy weight management and reduce disease risk.

Potential downsides of the blood type diet

The nutritional guidelines of the blood type diet can be restrictive and costly due to the required specialty and organic products.

Furthermore, the diet does not consider individual health issues and makes suggestions solely based on blood type. It can lead to nutrient deficiencies and encourage harmful eating behaviors.

Instead of following the blood type diet, it is better to consume a variety of nutrient-dense foods and make sustainable and realistic choices for overall health.

Scientific research on the blood type diet

There is limited research supporting the idea that eating for a specific blood type affects health.

According to nutritionists from the American Council on Science and Health, the diet lacks consistency and logical reasoning, making broad generalizations about billions of people’s eating habits.

• A 2013 review published in the American Journal of Clinical Nutrition found no evidence to support the health benefits claimed by the diet.
• In a 2013 review published in the journal PLOS, researchers examined the effect of blood type diets on heart disease indicators and found the observed changes in risk factors were associated with better food quality rather than eating for a specific blood type.
• A comprehensive review by the Belgian Red Cross concluded that there is no evidence supporting the benefits of the blood type diet, although it may result in weight loss due to its restrictive nature.
• A 2014 study indicated that following a blood type diet led to improved health outcomes, but similar effects were observed in unmatched blood type groups. This suggests that the reported health benefits are not exclusive to a specific blood type.
• A 2018 study published in the Journal of Nutrition found no significant health effects of the blood type diet on overweight adults.

From

Nutrition and Healthy Eating Resources

Nutrition and Healthy Eating Resources