The study did not evaluate the biological processes behind blood type and heart disease risk.
"Blood type is very complicated, so there could be multiple mechanisms at play," Qi said.
However, there is evidence suggesting that type A is associated with higher levels of low-density lipoprotein cholesterol, the waxy substance that can clog arteries, and type AB is linked to inflammation, which may affect the function of the blood vessels. Also, a substance that plays a favorable role in blood flow and clotting may be higher in people with type O blood.
Understanding blood type could help healthcare providers better tailor treatments, Qi suggested. For example, a patient with type A blood may best lower heart disease risk by decreasing cholesterol intake.
The study group was predominantly Caucasian, and it's not clear whether these findings would translate to other ethnic groups. Environment also contributes to risk, Qi said.
"It would be interesting to study whether people with different blood types respond differently to lifestyle intervention, such as diet," Qi said, noting that further analysis is needed.
Story provided by ConsumerAffairs.