1. Blood Type A, B or AB
Know your blood type? According to the Harvard School of Public Health, people with type A, B, or AB blood—that’s over half the population—have a slightly higher risk of heart disease compared to those with type O blood. Type A blood boosted the risk by five percent, type B by 11 percent and type AB by 23 percent. Researchers aren’t sure why the differences exist, but there’s evidence that type O blood may flow better and clot less, and other types may be higher in bad cholesterol.