14/03/2026
Your blood type may quietly influence the risk of stroke at a younger age
A large genetic analysis suggests that a person’s blood type may play a small but measurable role in the risk of having a stroke earlier in life. Researchers examined genetic data from hundreds of thousands of people, focusing on strokes that occurred before the age of sixty. They found that individuals with blood type A showed a slightly higher risk of early stroke compared with those who had blood type O, who showed a lower risk.
The difference appears to be connected to how blood clots form. Blood type influences proteins involved in clotting and how platelets behave inside blood vessels. People with blood type A tend to have higher levels of certain clot related factors, which may make the blood slightly more prone to forming clots under specific conditions. In contrast, blood type O is associated with lower levels of these factors, which may offer some protection.
Importantly, the researchers did not find the same strong pattern for strokes occurring later in life. This suggests that blood type plays a role mainly when other age related risk factors are still low. Scientists emphasize that blood type alone does not cause stroke and should not be seen as a prediction tool. Lifestyle factors like blood pressure, smoking, diabetes, and physical activity remain far more important in determining overall stroke risk.
Research Paper 📄
DOI: 10.1212/WNL.0000000000201006
