Can your blood type influence your chances of getting a stroke at a young age? According to a recent study, the answer is yes, especially if you have blood group A. The study, which analysed data from 48 earlier genetic studies, found that people with blood type A may have a 16 per cent higher chance of having a stroke before the age of 60, compared to other blood groups. On the other hand, people with blood group O, the most common blood type globally, had a 12 per cent lower risk of early stroke.

This large-scale analysis included genetic data from nearly 17,000 people who had suffered an ischemic stroke (the most common type of stroke, caused by a blood clot) before the age of 60. The findings were published in 2022 and offer deeper insight into how genetic and biological factors can play a role in serious health conditions like stroke.

What makes blood types different?

Your blood type—A, B, AB, or O, is determined by specific chemicals, called antigens, that are found on the surface of red blood cells. These antigens are inherited from your parents and are linked to your genes, specifically the ABO gene. Differences in these antigens can affect how blood clots and how your body responds to inflammation and injury.

Why blood type a may increase stroke risk

Researchers believe that people with blood type A tend to have higher levels of clotting proteins, such as von Willebrand factor and factor VIII. These proteins can make the blood more likely to clot, raising the risk of blockages in blood vessels, one of the main causes of strokes.

In contrast, people with blood type O generally have lower levels of these clotting factors, which may offer some natural protection against early stroke.

Blood types B and AB were also studied. They appeared to have a weaker link with stroke risk, but in certain populations, especially in East Asia, blood type AB may carry a slightly higher stroke risk as well.

Should you be worried?

Experts say these findings should not cause panic. Your blood type is just one of many factors that can influence stroke risk. Lifestyle factors such as diet, exercise, smoking, alcohol use, and managing conditions like high blood pressure play a much bigger role overall.

Also, while the 16 per cent increased risk for blood type A may sound alarming, it is a relatively small increase in the bigger picture. The researchers explain that blood type is a “notable but not dominant” risk factor, especially for younger people.

In older adults, stroke is often linked more to blocked arteries due to cholesterol buildup, rather than clotting issues related to blood type.

If you have blood type A, you may carry a slightly higher risk of having a stroke before age 60. But this doesn’t mean you’re destined to have one. Knowing your risk can help you take proactive steps like staying active, eating well, and going for regular health checks.

Your blood type may be written in your genes, but your health outcomes are still largely shaped by your everyday choices.