|Disease||Hypercholesterolemia (Elevated cholesterol)|
|Blood Group Link||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. (33)
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.
(Whincup PH, Cook DG, Phillips AN, Shaper AG. ABO blood group and ischaemic heart disease in British men. BMJ 1990 Jun 30;300(6741):1679-1682
Rh- 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.
Simple solutions to complex problems are very attractive. About one third of heart attacks occur in people over the age of 80. In about half of these cases, the victims have normal blood cholesterol levels. Of the remaining heart attack victims, only half have a modifiable risk factor, such as smoking, high blood pressure, or high cholesterol. The others have no risk factors. They exercise, do not smoke, are not overweight, and have normal blood pressure and cholesterol. Therefore, only about 10-15% of heart attacks are theoretically preventable by lowering blood cholesterol. Since this cannot be done effectively in many cases, the probability is that lowering of blood cholesterol probably prevents less than 10% of heart attacks. In addition, there are numerous well-documented paradoxes which seem to balk at all efforts to explain them away:
+ Studies on several African tribes of central Kenya and the Rift Valley have shown that intakes of enormous amounts of animal fat do not necessarily raise blood cholesterol; on the contrary, it may be very low. Samburu people, for instance, eat about a pound of meat and drink almost two gallons of raw milk each day during most of the year. Milk from the African Zebu cattle is much fattier than cow's milk, which means that
the Samburus consume more than twice the amount of animal fat than the average American, and yet their cholesterol is much lower, about 170 mg/dl . + Shepherds in Somalia eat almost nothing but milk from their camels. About a gallon and a half a day is normal, which amounts to almost one pound of butter fat, because camel's milk is much fattier than cow's milk. But although more than sixty percent of their energy consumption comes from animal fat, their mean cholesterol is only about 150 mg/dl, far lower than in most Western people. + According to the view of the Masai people in Kenya, vegetables and fibers are food for cows. They themselves drink half a gallon of Zebu milk each day, and their parties are sheer orgies of meat. On such occasions several pounds of meat per person is not unusual. In spite of that, the cholesterol of the Masai tribesmen is among the lowest ever measured in the world, about fifty percent of the value of the average American . + The Pima Indians of Arizona are mostly obese, have a diet of foods fried in lard, yet have heart attacks at a rate of only one quarter that of the rest of the population.
What is perhaps worth noting here is the fact that virtually all of these tribes are characterized by high percentages of O type blood as compared with A or B. (Moruant) And most of these societies have had a long tradition of hunter gathering versus agrarian existence. This can be demonstrated by looking at the distribution of blood type in Africa along the lines of latitude (north/south).
Starting at the top of the African continent, and working our way south, one passes progressively first through the uninhabitable Sahara desert, then through a belts of Savannah characterized by sparse rainfall and scattered trees, and finally to the forest or jungle zone. Evidence suggests that the Savannah country received the Neolithic cultural revolution at a rather early date, undoubtedly from Egypt, and supported a cereal based agriculture very early on, while the forest zone was still inhabited by hunter-gatherers for several thousand years later. What is especially fascinating is that along the entire belt, from the Atlantic Ocean to the Indian, the percentage of type O rises dramatically (to almost 80%) and with remarkable regularity, as one heads south to the hunter-gatherer based forest country.
Although the diet of the native Inuits of Greenland is high in seafood containing n-3 polyunsaturated fatty acids, advanced as the reason why their rates of coronary artery disease is very low, (considering that there are very few Italian restaurants that far north to provide the benefits of a Mediterranean diet) it is a little-known fact that this group has among the world's highest percentage of blood type O in their population, approximately 98%.
One of the most surprising facts about cholesterol is that there is no clear relationship between the blood cholesterol level and the degree of atherosclerosis in the vessels. If a high cholesterol really did promote atherosclerosis, then people with high cholesterol levels should have more atherosclerosis than people with low cholesterol.
Curiously, this basic fact has been known since the 1930's.(23). When, to their surprise, researchers found absolutely no correlation between the amount of cholesterol in the blood and the degree of atherosclerosis in the arteries of a large number of individuals who had died violently. This was again verified by a long-term study of 800 Canadian war veterans(24) which also did not find any connection either between the degree of atherosclerosis and the blood cholesterol level; those who had had a low cholesterol had just as much atherosclerosis when they died as those who had had a high cholesterol.
Similar studies have been performed in India (25), Poland (26), Guatemala (27), and in the USA (28), all with the same result: no correlation between the level of cholesterol in the blood stream and the amount of atherosclerosis in the vessels. Yet these studies are never cited by the proponents of the cholesterol-atherosclerosis argument.
We shouldn't take this wealth of conflicting evidence to imply that cholesterol is completely innocent! Rather, we should understand that the main reason we have such controversy is that the researchers did not take their analysis further and account for individual differences, such as blood type.
|References||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