Summary: Studies show that some health problems, including diabetic neuropathy and pancreatic pain, are more common in certain blood types. Most people know their blood type from birth. So it is a simple, low-cost way to gauge the risk of many health problems. Now, a new study shows that people with blood type A have a higher stroke risk than people with blood type O.
Heart and blood vessel problems like heart attack and stroke are among the top causes of death in the US and worldwide. There is also a worrying rise in strokes in young adults, those younger than 60. Of course, habits like too little exercise, poor food choices and other things around us are the main causes of events like stroke. Still, it is no secret that genes play a role.
For example, people with a family history of heart disease and stroke are more likely to have these problems at a younger age. Doctors know a bit about genetic risks. So they can run complex gene scans or tests to find the risk. This can help young adults prepare. People with a higher stroke risk can take extra steps, like changing their habits or even taking medicine to prevent problems.
But scanning a person’s genes is a hassle. So researchers keep looking for simple ways to spot stroke risk in different groups. One simple way to spot the risk of many health problems, including stroke, is blood type. Does a higher stroke risk in young adults have anything to do with blood type? For example, is there a real difference between blood types A, AB, B and O?
Blood type is often tied to certain genes. Most people know their blood type from birth. So it is a very practical, low-cost way to gauge the risk of many illnesses, including stroke. That is why researchers set out to see if blood type and stroke risk are linked. The study on this was recently published in the journal Neurology. It was a meta-analysis, a study that pools data from earlier studies on a topic. Pooling data from many high-quality studies gives more reliable results. The researchers included 48 studies with 17,000 stroke patients and 600,000 healthy adults.
The study found that people with blood type A were more likely to have an early stroke than people with blood type O. Both early and late stroke risk were somewhat higher in type A than in type O. After adjusting for things like age and sex, the extra risk in type A was only moderate. The risk of stroke in blood type A was about 16% higher than in people who never had a stroke. For blood type O, the risk was 12% lower.
These findings matter, but they show only a moderate rise in risk. Researchers say it is no cause for panic. People with blood type A should not worry. These findings mean they should take extra steps, like healthy habits and regular checkups. Researchers say it is a bit puzzling why stroke risk is higher in type A. Science still doesn’t know what causes more strokes in this blood type. Researchers think it may come from higher levels of certain proteins in the blood. Those proteins may raise the risk of blood clots in the legs, called deep vein thrombosis. Future studies must find out what drives this extra risk, because that would help find better ways to prevent it.
Frequently asked questions
Does your blood type affect your stroke risk?
Yes, a little. A meta-analysis in the journal Neurology pooled 48 studies covering about 17,000 stroke patients and 600,000 healthy adults. People with blood type A were more likely to have a stroke before age 60. People with blood type O were less likely. After adjusting for age and sex, the extra risk for type A was only moderate. So blood type is one marker among many.
Which blood type has the highest risk of early stroke?
In this study, blood type A. Compared with people who never had a stroke, type A carried about 16% higher risk, while type O carried about 12% lower risk. The difference showed up for both early and late strokes. It matters most for adults younger than 60, the age group where doctors now see a worrisome stroke trend.
Why would blood type A raise the risk of stroke?
Nobody knows yet. Researchers suspect that people with type A carry more of certain proteins in their blood, which raises the chance of clots forming, including clots in the leg veins known as deep vein thrombosis. Future studies need to confirm this mechanism before it can guide prevention.
If I have blood type A, what should I do?
Do not panic. The added risk is moderate, and habits still drive most strokes: too little exercise, poor food choices and things around us. Use your blood type as a reason to act early. That means healthy habits, regular checkups, and a frank talk with your doctor, especially if heart disease or stroke runs in your family.
Dr. Gurpreet Singh Padda, MD, MBA, MHP
