Blood Type A Linked to Higher Early Stroke Risk

New research indicates that specific blood types may elevate the risk of early stroke, particularly type A. The study suggests genetic and clotting-related factors could play a significant role.

Increased Risk for Type A

A recent study established a connection between blood type and early stroke risk. Individuals with blood type A showed a 16% increased likelihood of stroke before age 60. Conversely, those with blood type O had a 12% reduced risk.

The analysis, encompassing 48 genetic studies and almost 17,000 participants who experienced ischemic strokes before 60, revealed a notable link between ABO blood groups and early stroke risk. These findings reinforce the understanding of how biological and genetic elements impact health outcomes.

Blood Type Specifics

Blood types (A, B, AB, and O) are determined by antigens on the surface of red blood cells. Random genetic mutations lead to distinctions in how these antigens are presented.

Evidence indicates individuals with blood type A face a higher risk of early stroke, showing a 16% greater chance of experiencing one before the age of 60. Those with blood type O, the most common, may have some protection, with a 12% lower stroke risk.

Blood types B and AB showed weaker associations. Some data suggests type AB might present the highest risk in certain populations.

Possible Mechanisms

• Individuals with blood groups other than A tend to have higher levels of clotting proteins, like von Willebrand factor and factor VIII, which can predispose them to early stroke.
• Genetic correlation of the ABO gene suggests a relationship to early stroke.
• Type A individuals might face a slightly elevated risk due to clot-related conditions like deep vein thrombosis.

These results suggest blood type can serve as a notable indicator of stroke risk at a young age, especially for type A. Early blood clotting risk is linked to clotting factors, while older age may lead to arterial blockages. A 2023 study published in *Nature* found that individuals with blood type A also have a higher risk of coronary artery disease compared to those with blood type O (Nature).

The stroke risk for blood type A is reportedly 16% higher in East Asia. Type B may also slightly increase stroke risk across all age groups, although the effect is less pronounced. While these evaluations indicate increased risk, they should not cause undue alarm regarding one’s blood type.