What blood type has the most dementia?

Does Your Blood Type Influence Dementia Risk?

It might sound surprising, but your blood type could play a role in your risk for developing dementia. While AB blood type is the rarest—found in just about 4 percent of people in the U.S.—research suggests it may come with a hidden downside.

A study tracking cognitive health over time found that individuals with AB blood were 82 percent more likely to develop thinking and memory issues that can progress to dementia, compared to those with other blood types. This doesn’t mean having AB blood guarantees cognitive decline, but it may signal a higher vulnerability.

Why does this happen? Scientists believe the answer may lie in how blood types affect the circulatory system. Type AB is linked to certain clotting factors and inflammation markers that could influence brain health over time. For instance, higher levels of a protein called factor VIII, often seen in AB individuals, may impact blood flow to the brain—potentially increasing the risk of vascular issues that contribute to dementia.

Still, blood type is just one piece of a much larger puzzle. Genetics, lifestyle, diet, exercise, and managing conditions like hypertension and diabetes play far more significant roles in cognitive health. Knowing your blood type might offer a clue, but it shouldn't cause alarm.

The real takeaway? Awareness matters. If you have AB blood, it’s not a sentence—it’s a nudge to be proactive. Focus on heart-healthy habits: eat well, stay physically and mentally active, manage stress, and keep up with regular check-ups. Protecting your brain isn’t about your blood type—it’s about the choices you make every day.