In general, type AB's are at a disadvantage due to the fact that they lack both anti-A and anti-B antibodies. These antibodies are often used as a preliminary line of defense against many microbes (which themselves can have ABO blood type antigens; a fact which clearly illustrates the limitation of using the term 'blood type' to describe them.) However, it appears that nature has provided AB's with a substitute method of achieving immune competency: They have the highest levels of Natural Killer (NK) cell activity of the ABO blood groups. Natural Killer (NK) cells, a small subset of peripheral blood lymphocytes, mediate a variety of functions that are important in human health and disease.

In addition to their role in control of metastasis and infections, NK cells participate in immunoregulation, red blood cell production, reproduction and neuroendocrine interactions. Defective or absent NK cell activity is associated with a spectrum of human diseases. Methods of keeping your NK cells happy read like a basic textbook of naturopathic medicine: Fresh air, sunlight, exercise, light diet, low stress. Type AB's who are prone to low resiatnce can invesitgate the Traditional Chinese herb Astragalus, which has quite a bit of research supporting its use in enhancing NK cell activity.

Uterine fibroids (benign tumors of the uterus, typically non-symptomatic unless embedded in the lining when they can cause heavy bleeding at menses) are more common in blood groups A and AB, probably due to the fact that cellular growth factors that are responsible for the proliferation of uterine tissue can be stimulated by the type A antigen. It has also been shown that hyperlastic (rapidly growing) endometrial tissue is heavily infiltrated with blood group antigens, whereas normal endometrial tissue is not.

Typically, the AB works well in lowering growth-stimulating polyamines, which can accelerate cellular turnover, especially by the use of soy products. Two herbal remedies traditionally used for treating uterine fibroids are Capsella or Shepherd's Purse and chlorophyll (the green pigment in plants). Capsella may have as its basis of action the fact that it is rich in fumaric acid which is known to inhibit excessive cellular turnover. As with any medical condition characterized by excess bleeding, it is prudent to make sure that the cause of the bleeding is indeed not from more serious reasons. As such one should always bring such occurances to the attention of one's gyneocologist or primary care phsyician.

There may be some information suggestive that being type AB blood may result in you more likely staying an essentially healthy 'carrier' rather than progressing to more dire consequences. An older investigation studied 457 'healthy' hepatitis B carriers.

The results obtained were analyzed according to the cases investigated. Differences were found between the distribution of blood groups among the normal unselected population and among 'healthy' carriers, where the incidence of blood type AB subjects was much higher than expected. I typically prescribe the following for chronic, but healthy hepatitis (B or C) patients: Licorice (exerts mild antiviral effects, also protective of the liver tissues), Catechin, a type of flavone anti-oxidant (exerts mild antiviral effect especially against hepatitis B). Non of these herbs are toxic and they can be used for long periods of time without any worry.