Knowing your blood type is important if you need a blood transfusion. But can it also tell you something about your risk of heart disease? Some researchers suspect that blood type can affect such risk factors as inflammation and levels of LDL,or bad cholesterol. But the notion has been a matter of some debate,prompting many studies. In 2006,a study of 2,000 coronary artery patients in The International Journal of Cardiology found no difference in the frequency of blood types in heart patients,compared with the general population. But since then,much larger studies have shown the opposite. One study in Italy of 5,000 heart patients found that blood types A,B and AB were associated with greater rates of cardiac mortality,compared with people who were type O. More recently,a team led by a Harvard researcher analysed data from two long-running studies with nearly 90,000 people. Compared with people with type O blood,those with type AB were 23 percent more likely to develop heart disease. People who were type A had a 5 percent higher risk,and those with type B had a roughly 10 percent greater risk than those with type O. Researchers caution that if blood type has any influence on heart disease risk,it is probably modest,and that unlike other risk factors,including diet and exercise,it is not something that can be controlled. THE BOTTOM LINE Some studies suggest that blood type may provide a small glimpse into heart disease risk,although more research is needed.
