Could your blood type quietly shape your stroke risk? A major study published in Neurology suggests it might, especially if you have blood type A.
Researchers examined genetic data from nearly 17,000 young stroke survivors and over 600,000 controls across several continents. Their findings spotlighted a compelling connection between early-onset stroke and the A1 subgroup of blood type A. In fact, people with this variation had a 16% higher risk of suffering a stroke before age 60 compared to other blood types. On the flip side, those with type O1 showed a 12% lower risk.
But before you start panicking about your blood type, here’s some perspective: strokes before age 60 are relatively rare, and the added risk tied to type A is modest. “We still don’t know exactly why this link exists,” said senior author Dr. Steven Kittner, a vascular neurologist at the University of Maryland. He suspects it has something to do with clot-promoting factors—like platelets and endothelial cells—that differ between blood types.
Interestingly, the association between type A and stroke risk fades after age 60, hinting that early strokes may have different biological triggers than strokes that strike later in life. In younger patients, strokes are less likely to stem from clogged arteries and more likely related to abnormal clotting.
Another finding: people with type B blood were 11% more likely to have a stroke, regardless of age.
This research contributes to a growing body of evidence linking the ABO gene region to heart health, including an increased risk of coronary artery calcification and venous blood clots.
The takeaway? Your blood type might offer subtle clues about your vascular health, but it’s only one piece of a much larger puzzle. Lifestyle and overall cardiovascular health remain the most important factors.
