The relationship between ABO blood phenotype and total serum cholesterol level was examined in a Japanese population to determine whether elevated cholesterol levels are associated with blood type A, as has been demonstrated in many West European populations. Their results showed that cholesterol levels were very significantly elevated in the blood type A group compared to non-A group (P < 0.00001). (2)
A study examining a total of 380 marker/risk factor combinations were analyzed, and associations were found between blood type A and both serum total cholesterol and low-density lipoprotein cholesterol, while a negative association was found between blood type B and serum total cholesterol. (3)
A Hungarian study measured the cholesterol of 653 patients who underwent coronary angiography between 1980 and 1985 in the Hungarian Institute of Cardiology. Their results showed that blood group A was more frequent and blood group O was less frequent than normally seen in the Hungarian population, and that there were difference between the blood types as to the areas of the vessels where the narrowing of the coronary arteries had occurred.(1)
In a nationwide sample of more than 6000 black and white adolescents aged 12 to 17 years, ABO blood group and coronary risk factor levels were measured. Blood group A1 was associated with significantly higher serum total cholesterol levels in white females independent of all other risk factors, in white males independent of age and weight, and in southern black females independent of age and weight. (4) A separate study (the Bogalusa heart Study) looked at 656 white and 371 black adolescents and found the same results with regard to cholesterol (A higher than others) and also showed higher levels of LDL lipoproteins in type A adolescents over the other blood types.
In an Italian study, total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol concentrations were evaluated in 393 Italian male blood donors. Triglyceride levels were higher in individuals with type B or type AB blood than in subjects without this antigen. We think that environmental factors could be more important than genetic factors in the arousal of cardiovascular diseases. (5)
Several forms of elevated lipoproteins are inherited. One of the more common forms of hyperlipoproteinemia is called Type IIB, and it is characterized by increased and LDL ('bad cholesterol') and VLDL ('really bad cholesterol'). Type IIB hyperlipoproteinemia is characterized by premature hardening of the arteries, obstruction of the carotid artery (the artery which supplies the head and brain), peripheral artery disease, heart attack and stroke. Since all of these disorders show higher rates of occurrence in blood type A, it is not surprising that studies have found a significant connection between a hyperlipoproteinaemia IIb and blood type A in both new-born and in patients after myocardial infarction.
Does this material imply that the only people who suffer from heart attacks are type A? Obviously, the answer is no. However what this material clearly shows is that blood type a new the group who gets heart attacks and cardiovascular diseases with the methodology that we best understand. By this I mean the link which has been so extensively documented in the last 20 years between low-fat diet, cholesterol levels and stress and heart disease. It should be quite clear by now to the reader that many of these strategies, advocated with such passion as a sort of "universal diet" seem to be best suited for the 41 percent of the public who are blood type A.
How much more has to be done before the medical world wakes up and begins to publicize the overwhelming fact that having type A blood is a serious risk factor for and heart disease by virtue of elevated cholesterol and excessive clotting?
Although we can see from the data that having blood type A or AB is clearly an important risk factor for heart and artery disease, and that the majority of cases are seen in these two blood groups, types O and B should not rest easy. Although they are certainly at less of a risk of developing problems due to clotting or high cholesterol than types A or AB, they still have get heart disease, albeit in lower numbers, and need to take precautions. However, as we will see, their precautions are distinctively different.
An eight-year study of 7662 men published in the prestigious British Medical Journal found Blood Type A is linked to a higher incidence of ischaemic heart disease, as well as having higher total serum cholesterol concentrations. Rh- status also shows an increased incidence of elevated cholesterol.
The NN subtype of the MN system is associated with a better than average response (especially with regard to LDL) to a reduction of dietary fat and cholesterol. The MN variant does OK (but not great) at reducing choelsterol via diet; the MN subtype has the least chance of dietary fat and cholesterol having any influence on cholesterol.
Elevated triglycerides is associated with group AB and B, which implies that the relationship is linked to the B gene.
1. Tarjan Z, Tonelli M, Duba J, Zorandi A [Correlation between ABO and Rh blood groups, serum cholesterol and ischemic heart disease in patients undergoing coronarography]. Orv Hetil 1995 Apr 9;136(15):767-9
2. Wong FL, Kodama K, Sasaki H, Yamada M, Hamilton HB. Longitudinal study of the association between ABO phenotype and total serum cholesterol level in a Japanese cohort. Genet Epidemiol 1992;9(6):405-418
3. George VT, Elston RC, Amos CI, Ward LJ, Berenson GS. Association between polymorphic blood markers and risk factors for cardiovascular disease in a large pedigree. Genet Epidemiol 1987;4(4):267-275
4. Gillum RF. Blood groups, serum cholesterol, serum uric acid, blood pressure, and obesity in adolescents. J Natl Med Assoc 1991 Aug;83(8):682-688
5. Contiero E, Chinello GE, Folin M. Serum lipids and lipoproteins associations with ABO blood groups. Anthropol Anz 1994 Sep;52(3):221-30