The Blood Type Diet is a nutritional concept suggesting that an individual’s ABO blood type dictates the foods they should consume for optimal health and disease prevention. This theory posits that each blood type evolved at a different time in human history, corresponding to distinct ancestral diets. The AB blood type is the most recent and rarest of the four types, found in less than five percent of the global population. It is hypothesized that this blood group carries a blend of the characteristics and challenges of both Type A and Type B. The dietary recommendations for AB individuals are designed to address this unique genetic profile.
Understanding the AB Blood Type Dietary Profile
The theoretical dietary profile for the AB blood type reflects a complex genetic inheritance from both Type A and Type B ancestors. Individuals are thought to share Type A’s predisposition for lower-than-average stomach acid production. This reduced digestive capacity means that certain foods, particularly animal proteins, may not be metabolized efficiently. The diet suggests that poorly digested food, especially meat, may subsequently be stored as fat.
The AB type also possesses some of Type B’s adaptive qualities, allowing for a broader tolerance of various food groups compared to the Type A diet. This dual inheritance results in a sensitive digestive system. AB types are theorized to be more reactive to certain food-based proteins, known as lectins, which are believed to agglutinate with their blood cells. The recommended dietary strategy is a moderated, mixed approach, leaning heavily toward a vegetarian base with selective additions of animal protein.
Recommended Food Groups and Beneficial Choices
The AB Blood Type Diet encourages a balanced and varied intake, often described as a modified omnivorous or near-vegetarian approach. Protein sources considered highly beneficial include specific types of seafood and poultry. Cold-water fish are recommended as excellent, easily digestible sources of protein. For poultry, turkey and rabbit are listed among the most beneficial meats for this blood type.
Seafood and Poultry
Salmon
Cod
Tuna
Mahi-mahi
Turkey
Rabbit
Dairy products, often problematic for other blood types, are generally well-tolerated by AB types, especially in their cultured forms. Beneficial dairy options are thought to be more compatible due to the presence of the B-like antigen in the AB blood structure. Tofu is also highly recommended as a primary source of plant protein to boost metabolism.
Dairy and Plant Proteins
Yogurt
Kefir
Cottage cheese
Feta
Goat cheese
Tofu
In the grains category, AB individuals are encouraged to consume foods that contain less gluten and are less likely to cause digestive issues. Beneficial grains include millet, oat bran, and oatmeal, which provide necessary fiber. Spelt and certain rice varieties are also considered neutral and acceptable additions to the diet. A wide array of vegetables is encouraged, particularly green leafy varieties, broccoli, and various squashes.
Grains and Vegetables
Millet
Oat bran
Oatmeal
Spelt
Rice varieties
Green leafy vegetables
Broccoli
Squashes
Foods to Limit or Exclude
The AB diet advises strict avoidance of certain foods believed to cause digestive distress or negatively impact metabolism. Due to the inherited low stomach acid levels, most red meats are discouraged. The diet specifically warns against all smoked or cured meats, citing a potential link to stomach cancer in individuals with this digestive profile. Chicken is also listed as a meat to avoid, as its lectins are theorized to cause an adverse reaction in the AB system.
Meats to Avoid
Beef
Buffalo
Venison
Veal
Smoked or cured meats
Chicken
Specific legumes and seeds are flagged for exclusion because their lectins are thought to interfere with AB blood type antigens. This includes kidney beans, lima beans, and several types of corn, which are believed to inhibit insulin efficiency. Certain grains, such as buckwheat, are also advised against consumption. These exclusions aim to mitigate the theory of lectin-induced agglutination.
Legumes, Seeds, and Grains to Avoid
Kidney beans
Lima beans
Corn
Buckwheat
Several common beverages and condiments are listed as items to limit or avoid entirely. Caffeine and alcohol are generally discouraged, especially during periods of high stress, as the AB type is theorized to be susceptible to stress-related adrenaline overproduction. The diet also suggests avoiding common items like black pepper and vinegar, proposing that they may irritate the sensitive stomach lining.
Scientific Perspective on the Blood Type Diet
Despite its popularity, the Blood Type Diet, including the specific recommendations for AB individuals, lacks robust clinical evidence to support its core claims. Mainstream nutritional science does not support the premise that an individual’s ABO blood type should determine their dietary needs. A comprehensive systematic review of the literature found no studies that demonstrate the health benefits of adhering to a blood type-specific diet. The theoretical mechanism of food lectins interacting negatively with blood antigens remains largely unproven in human clinical trials.
The health improvements reported by some individuals following the diet can often be attributed to other factors. The diet is highly restrictive and generally eliminates many processed foods, refined sugars, and simple carbohydrates. This is a common feature of many successful weight loss or health-improvement plans. Studies have shown that when people follow a diet similar to one recommended for a specific blood type, the health benefits observed apply to people of all blood types. Therefore, while the diet encourages healthier overall eating habits, the claimed link between blood type and food compatibility is not validated by empirical research.