Can you plan your perfect diet based on your blood type?
A new trend hitting the nutrition shelves is the blood type diet. However, despite its new found fame, this is not a new concept. Naturopathic physician Dr. D’Adamo created the blood type diet in 1996, based on the idea that eating foods compatible with your blood type will help you to stay healthy, improve your digestion and nutrients absorption, and maintain a normal weight. The diet is also said to be beneficial for weight loss, one of the key reasons for its popularity.
The diet provides a list of foods that each blood type; O, A, B, or AB, should and should not consume. It is thought that eating foods that are not compatible your specific blood type could have a health-damaging effect.
Scientists have not found any proof to support Dr. D’Adamo’s theory so far. Thus, the blood type diet is considered to be controversial by most nutritionists and medical professionals. Despite the fact that this concept is supported by only a few authors and has very little, if any, scientific proof backing its efficiency, people all over the world are signing up for the blood type diet. This article will make an attempt to explain everything you need to know about it.
What are the blood types?
Blood is made of blood plasma, red blood cells (erythrocytes) and white blood cells (leukocytes). What makes the blood types different is the presence of various antibodies within the plasma and inherited antigens on the surface of the red blood cells. These antigens are different in origin and can be carbohydrates, proteins, glycoproteins, and glycolipids.
Different blood types contain different antibodies and antigens:
- Blood type O: contains both, anti-A and anti-B antibodies in the plasma, but no antigens in the red blood cells.
- Blood type A: has anti-B antibodies in the plasma and anti-A antigens in the red blood cells.
- Blood type B: is opposite from A as it contains anti-A antibodies and anti-B antigens.
- Blood type AB: has no antibodies in the blood plasma, but contains both types of antigens in the red blood cells.
The blood type of a newborn is always inherited and is a predictable combination of both parents’ blood type.
Rh factor is the second most important blood type system. When the blood type is marked, the Rh factor is commonly represented as negative (-) or positive (+) following the ABO symbol. The presence of the Rh(D) antigen, one of the 49 antigens of the Rh blood group system, is used to determine if the person has an Rh positive, meaning Rh(D) is present, or Rh negative, meaning Rh(D) is not present.
Supporters of the blood type diet claim that different blood groups are genetically predetermined to consume specific foods and involve in different levels of physical activity. This idea connects the blood types with specific evolutionary paths of humans as a species.
The connections are as following:
- O blood type – hunter-gatherers
- A blood type – farmers
- B blood type – nomads (livestock herders)
- AB blood type – a combination of farmers and livestock herders
The main point of those who advocate the blood type diet is that the digestion of lectins, which are the carbohydrate-binding proteins found in many foods, varies significantly between different blood groups. Therefore, this theory suggests that people who consume foods which are naturally unfit for their blood type will experience various health problems.
What are the Claims of Blood Type Diet Advocates?
Advocates of the Blood Type Diet claim that lectins, which are proteins commonly found in many kinds of edible plants, beans, and dairy products, can bind with the antigens found on the surface of red blood cells and cause them to clump. Thus, avoiding or limiting the intake of lectins will have a positive effect on the general health.
While lectin proteins can have a negative effect on the body, they can have positive effects as well. Many studies have shown that cooking such foods greatly reduces quantity and effect of lectins, thus debunking one of the main corner stones of this diet.
The diet also includes a number of proven, health-beneficial, routines such as drinking plenty of water, limiting the intake of carbs and fats, and being physically active. Thus those who do well on the diet may simply just be doing well due to the fact they are on a more restrictive eating plan.
The Recommended Dietary and Exercise Plans
In its essence, the Blood Type Diet is very simple. Like many other diet and weight-loss programs, it involves restrictions on certain foods and recommends a type of physical activity. The only difference is that the diet and exercise plans are made specifically for each blood type.
O Blood Type
This blood type is found in just under half of the population worldwide and is recognized as ancestral. It is associated with the hunter-gatherer lifestyle and therefore it is presented as a high-protein meal plan similar to the more famous Atkins and Ketogenic diets.
Foods to avoid are mostly those with higher content of carbohydrates such as all types of grain (wheat, corn, oats, etc.), alcohol, caffeine, and even dairy products.
Recommended foods include most meats (beef, lamb, pork, venison, turkey, etc.) preferably grown in organic conditions. Fresh fruits and vegetables are also recommended.
As for exercise, the O – blood type is considered to require intense physical activity similar to the routine of our ancestors who were constantly on the move while hunting and gathering food. In modern times this translates into jogging, hiking, cycling, swimming, gymnastics, and other energy-consuming activities.
A Blood Type
The A – blood type is completely opposite from the O – type, as it draws the evolutionary parallel with the farmers’ diet of the agrarian era. People with this blood group are encouraged to avoid meats and enjoy a predominately vegetarian diet.
The main sources of protein are soy, legumes, and green vegetables such as broccoli and asparagus. Fruits are also recommended. All foods are to be consumed raw or as close as they can be to their natural state.
The exercise plan is not very rigorous. Physical activity should be light and focused on relieving stress. Yoga, tai chi, swimming, hiking, and golfing are recommended.
B Blood Type
People with the B – blood type are considered descendants of our nomadic, livestock herding, ancestors. These people are omnivores, in a sense that animal proteins, grains, and vegetables are all allowed. However, there are some restrictions.
Corn, lentils, tomatoes, sesame seeds, and chicken are to be avoided. Meats such as mutton, lamb, goat, turkey, salmon, and rabbit are recommended as well as eggs and dairy products.
Physical activity is not considered essential for people with the B – blood type. Lighter activity such as swimming, hiking, and yoga can be performed several times a week on a moderate intensity level.
AB Blood Type
As its name suggests, this blood group combines the traits of A-type and the B-type. The result is a mostly vegetarian diet with a controlled addition of lean meats as a source of animal protein. The sources of this protein should be mostly turkey and fish. The rest of the diet plan is made up of grains, fresh fruits, and vegetables.
Tofu, seafood, yogurt, and kefir are also allowed while caffeine, alcohol, red meats, and smoked meats are not recommended.
Exercise should not be too intense. The main goal is to relax, relieve stress, and channel the kinetic energy without leaving the comfort zone. Yoga, tai chi, gymnastics, and stretching exercises are recommended.
What Does The Science Say?
The Blood Type Diet is restrictive, but it promotes an active lifestyle and a meal plan rich in organic whole foods. Scientists agree that these two are very important for maintaining a healthy weight and can be beneficial for health. However, there is no scientific evidence to support the claim that the relationship between specific diets and corresponding blood types is responsible for this.
Some research has been done on this subject. One study performed at the University of Toronto, Canada, in 2014 found no evidence to back the Blood Type Diet theory. In this research, the scientists focused on particular “health markers” which included cholesterol, insulin, and triglycerides levels and observed the effect of the Blood Type Diet on them.
1,455 healthy, adult participants took part in the study over the equal period of time. The conclusion was that there is no difference between the observed “health markers” in individuals who continued with their usual diet and those who took up a diet specially designed to match their blood type. Thus, the Blood Type Diet theory was proclaimed false.
What is in our blood can provide a lot of information, including warning signs for many processes. The risks for many diseases, especially cardiovascular ones (heart attack, stroke, etc.) and diabetes can be assessed in a reliable and timely manner by analyzing the blood. The foods we eat and the lifestyle we indulge in can have a great impact on those factors, but this does not imply that a specific blood type requires a particular exercise pattern or a diet.
Chances are that the success (if there is any?) of the Blood Type Diet is a consequence of a well-balanced routine of eating healthy and being active. It is also necessary to state that the Blood Type Diet does not seem to be a harmful one, although it can be restrictive. After all, whatever is the reason for someone to enjoy a diet rich in fresh fruits and vegetables, lean meats, organic and whole foods, while drinking plenty of water and exercising, it is a good one.
The Final Word
Although different blood types can be associated with certain genetic predispositions, there is no evidence to support the claim that specific dietary plans are health-beneficial for specific blood groups. Many recommendations which are included in this diet such as eating low-carb foods, being mostly vegetarian, and increasing the levels of physical activity can, however, result in weight-loss and the improvement in general health, regardless of the blood type.