An American naturopath and his father have discovered scientific and chemical evidence that your blood type is the most important factor in determining your diet and your susceptibility to illness.
Peter D'Adamo is a second generation naturopathic physician. His father, Dr James D'Adamo noticed a certain number of patients not only didn't improve on vegetarian, low fat diets, but did worse. D'Adamo Senior reasoned that since blood was the fundamental source of nourishment to the body, perhaps some aspect of the blood could help to identify differences in individual dietary needs.
Through the years and with countless patients, certain patterns began to emerge concerning diet and blood types.
Peter D'Adamo himself has spent many years studying the association between blood type, diet and certain diseases.
Although many of his views stand up to scientific scrutiny, readers should be advised that they are controversial, as they indicate that certain groups should eat meat. Nevertheless, we are publishing his theories for the insight they could provide about the nature of disease. Editor.
Your blood type is the key to your body's entire immune system. It controls the influence of viruses, bacteria, infections, chemicals, stress and the entire assortment of invaders and conditions that might compromise your immune system.
Nature has endowed our immune systems with very sophisticated methods to determine if a substance in the body is foreign or not. One method involves chemical markers called antigens, which are found on the cells of our bodies. Every life form, from the simplest virus to humans themselves, has unique antigens that form a part of their chemical fingerprint. One of the most powerful antigens in the human body is the one that determines your blood type. The different blood type antigens are so sensitive that when they are operating effectively, they are the immune system's greatest security system. When your immune system sizes up a suspicious character (ie, a foreign antigen from bacteria) one of the first things it looks for is your blood type antigen to tell it whether the intruder is friend or foe (see box, below).
Antibodies are the cellular equivalent of the military's smart bomb. The cells of our immune system manufacture countless varieties of antibodies, and each is specifically designed to identify and attach to one particular foreign antigen. A continual battle wages between the immune system and intruders who try to change or mutate their antigens into some new form that the body will not recognize. The immune system responds to this challenge with an ever increasing inventory of antibodies.
When an antibody encounters the antigen of a microbial interloper, a reaction called agglutination (gluing) occurs. The antibody attaches itself to the viral antigen and makes it very sticky. When cells, viruses, parasites and bacteria are agglutinated, they stick together and clump up, which makes the job of their disposal all the easier. Sweeping the system of odd cells, viruses, parasites and bacteria, the antibodies herd the undesirables together for easy identification and disposal.
A chemical reaction also occurs between your blood and the foods that you eat. It is amazing but true that today, in the late twentieth century, your immune and digestive systems still maintain a favouritism for foods that your blood type ancestors ate.
We know this because of a factor called lectins. Lectins, abundant and diverse proteins found in foods, have agglutinating properties that affect your blood. Lectins are a powerful way for organisms to attach themselves to other organisms in nature. Lots of germs, and even our own immune systems, use this superglue to their benefit. For example, cells in our liver's bile ducts have lectins on their surfaces to help them snatch up bacteria and parasites. Bacteria and other microbes have lectins on their surfaces as well, which work rather like suction cups, so they can attach to the slippery mucosal linings of the body. Often, the lectins used by viruses or bacteria can be blood type specific, making them a stickier pest for a person of that blood type.
So, too, with the lectins in food. When you eat a food containing protein lectins that are incompatible with your blood type antigens, the lectins target an organ or bodily system (kidney, liver, brain, stomach, etc) and begin to agglutinate blood cells in that area.
Many food lectins have characteristics that are close enough to a certain blood type antigen to make it an "enemy" to another. For example, milk has B like qualities; if a person with Type A blood drinks it, their system will immediately start the agglutination process in order to reject it.
Here's an example of how a lectin agglutinates in the body. Let's say a Type A person drinks a glass of milk. The milk is digested in the stomach through the process of acid hydrolysis. However, the lectin protein is resistant to acid hydrolysis. It doesn't get digested, but stays intact. It may interact directly with the lining of the stomach or intestinal tract, or it may get absorbed into our bloodstream along with the digested milk nutrients. Different lectins target different organs and systems.
Once the intact lectin protein settles somewhere in your body, it literally has a magnetic effect on the cells in that region. It clumps the cells together and they are targeted for destruction, as if they, too, were foreign invaders. This clumping can cause irritable bowel syndrome in the intestines, cirrhosis of the liver, or it could block the flow of blood through the kidneys to name just a few of the effects.
For the most part, our immune systems protect us from lectins. Ninety five per cent of the lectins we absorb from our typical diets are sloughed off by the body. But at least 5 per cent of the lectins we eat are filtered into the blood stream, where they react with and destroy red and white blood cells. The actions of lectins in the digestive tract can be even more powerful. There, they often create a violent inflammation of the sensitive mucus of the intestines, and this agglutinative action may mimic food allergies. Even a minute quantity of a lectin is capable of agglutinating a huge number of cells if the particular blood type is reactive.
The key is to avoid the lectins that agglutinate your particular cells determined by blood type. Lectins vary widely according to their source. For example, the lectin found in wheat has a different shape and attaches to a different combination of sugars than the lectin found in soya, making each of these foods dangerous for some blood types, but beneficial for others.
Many people with arthritis feel that avoiding the "nightshade" vegetables such as tomatoes, aubergines and white potatoes, seems to help their arthritis. That's not surprising, since most nightshades are very high in lectins.
There are many causal factors for disease that are clearly influenced by blood type. For instance, Type As with a family history of cardiovascular disease should examine their diets very carefully. Red meats and saturated fats of all kinds are poor choices for a digestive tract ill suited to processing them, and which produces higher levels of both triglycerides and cholesterol in Type As. The friendly Type A immune system is also more prone to cancer, since it has a hard time recognizing foes.
Type Os are very sensitive to the agglutinating lectin found in whole wheat. This lectin interacts with the lining of the Type O intestinal tract and produces additional inflammation. If you're Type O and suffer from Crohn's disease, colitis or irritable bowel syndrome, wheat acts like a poison in your system. Although the Type O immune system is generally hardy, it is also limited. Original Type Os had fewer microbes to conquer, and the blood type does not adapt easily to the complex viruses prevalent today.
The disease profiles of Type Bs are independent of Type O and Type A by virture of the idiosyncratic B antigens. they tend to be susceptible to slow moving, sometimes bizarre, viral diseases that don't manifest themselves for many years like multiple sclerosis and rare neurological aiments sometimes triggered by the lectins in foods such as chicken and corn.
Type ABs have the most complex disease profile, since they possess both A like and B like antigens. Most of their disease susceptibilities are A like, so if you had to categorize them you would say they are more A than B.
My own patients habitually term any reaction to something they've eaten a "food allergy", although most of the time it is not an allergy they are describing, but rather a food intolerance.
Type Os are more likely to be asthma sufferers, and even hay fever, the bane of so many lives, appears to be specific to type O bloods.
Many food lectins, especially wheat, interact with immunglogin E (IgE) antibodies found in the blood. These antibodies stimulate white blood cells called basophiles to release not only histamines, but other powerful chemical allergens called kinins. These can cause severe allergic reactions such as the swelling of throat tissues and contricting of the lungs.
Type Os who eliminate wheat often relieve many of their symptomatic behaviours, such as sneezing, respiratory problems, snoring or persistent digestive disorders.
Type Os are also the main sufferers of arthritis. Type O immune systems are environmentally intolerant, and there are many foods grains and potatoes among them whose lectins produce inflammatory reactions in their joints.
Both multiple sclerosis and ALS (amyotrophic lateral sclerosis) occur in blood Type B with very high frequency. It's an example of the Type B's tendency to contract unusual slow growing viral and neurological disorders. The Type B association may explain why Jews, a high number of which are Type B blood, suffer these diseases more than others. Some researchers believe that multiple sclerosis and ALS are caused by a virus, contracted in youth, that has a B like appearance. The virus cannot be combated by the Type B immune system since it is unable to produce anti B antibodies. The virus grows slowly and without symptoms for twenty or more years after entering the system.
Type As constitute the greatest number of pernicious anaemia sufferers, but the condition has nothing to do with the vegetarian Type A diet. Pernicious anaemia is the result of vitamin B12 deficiency, and Type As have the most difficulty absorbing B12 from foods.
The reason for the deficiency is that the body's use of B12 requires high levels of stomach acid and the presence of intrinsic factor, a chemical produced by the lining of the stomach And responsible for B12's assimilation. Type As and Type ABs have lower levels of intrinsic factor than the other blood types, and they don't produce very much stomach acid.
In the late 1960s the Framingham (Massachusetts) Heart Study discovered a strong connection between blood type and who survives heart disease. The study found that Type O heart patients, between the agest of 39 and 72, had a much higher rate of survival than Type A heart patients in the same age group. This was especially true for men between the ages of 50 and 59.
High alkaline phosphatase levels, which speed the absorption and metabolism of fats, lead to low cholesterol levels in the blood. Type O blood normally has the highest matural levels of this enzyme. In Type B, Type AB and Type A, the alkaline phosphatase enzyme is seen in ever declining levels, with Type B having the highest level after Type O.
Another element to Type Os' high survival rate is blood clotting factors. Type Os have fewer clotting factors in their blood. This defect in Type O blood may actually work to their advantage, as this essentially thinner blood is less likely to deposit the plaque that will clog the arterial flow. On the other hand, Type As, and to a slightly lesser extent, Type ABs, have a consistently higher level of serum cholesterol and triglycerides than do Type O and Type B blood.
Type Os tend to develop the more ulcerative form of colitis that causes bleeding with elimination. This is probably due to the lack of adquate clotting factors in their blood. Type As, Type ABs and Type Bs tend to develop more of a mucous colitis, which is not as bloody. It has been known since the early 1950s that peptic ulcer of the stomach is more common in Blood Type O, with the highest occurrence in Type O non secretors. Type Os also have a high rate of bleeding and perforation. One reason is that Type Os have higher stomach acid levels and an ulcer producing enzyme called pepsinogen.
In December 1993, researchers at Washington University School of Medicine in St Louis reported in the Journal of Science that people with Type O blood are a favourite target for the bacteria now know to cause ulcers. This bacteria, H pylori, was found to be able to attach itself to the Type O antigen lining the stomach, and then work its way into the lining.
Many bacteria prefer specific blood types. In fact, one study showed that over 50 per cent of 282 bacteria carried antigens of one blood type or another.
It has been observed that viral infections in general seem to be more frequent in Type Os because they do not possess any antigens. These infections are less frequent and milder in Type A, Type B and Type AB.
Adapted from The Eat Right Diet by Peter D'Adamo, ND (Century, 1998. lb6.99).