Why your blood type might predict your risk of stroke: Type A is most susceptible — but type 0 least, study finds
- US researchers reviewed dozens of studies on genetics and ischemic stroke
- People with blood group A are 16 percent more likely to develop the disease before the age of 60
- The risk was lower for those with the most common type O and slightly increased for B
A person’s blood type can be linked to their risk of an early stroke, according to research.
US researchers reviewed dozens of studies on genetics and ischemic stroke, the most common type.
They found that people with blood type A were 16 percent more likely to have one before the age of 60 compared to everyone else.
The link remained even after other risk factors, such as gender, weight and whether or not they had smoked, were filtered out.
People with blood type B had a slightly increased risk of stroke – but the risk was lower for those with the most common blood type O.
The researchers said the increased risk, even for type A, is small and people shouldn’t worry.
It’s unclear why blood type seems to play a role in stroke risk, but it’s thought to affect a person’s risk of developing dangerous blood clots.
A person’s blood type can be linked to their risk of early stroke – with type As most at risk (file)
Ischemic strokes occur when a blood clot cuts off blood and oxygen to the brain, and they account for nearly nine out of ten strokes.
Blood clots typically form in areas where the arteries have become narrowed or blocked over time by fatty deposits called plaques
In the latest study, a team from the University of Maryland analyzed data from 7,000 stroke patients and nearly 600,000 healthy people from 48 different studies.
Breakdown of British and Americans by Blood Type
• O positive: 35%
• O negative: 13%
• Positive: 30%
• Negative: 8%
• B-positive: 8%
• B negative: 2%
• AB positive: 2%
• AB negative: 1%
Source: 900,000 blood donors in the NHS Blood and Transplant Registry
• O negative: 7%
• Positive: 34%
• Negative: 6%
• B-positive: 9%
• B negative: 2%
• AB positive: 3%
• AB negative: 1%
Source: San Diego Blood Bank
They found that people with O blood before their 60th birthday had a 12 percent reduced risk of having a stroke, while types B and AB had no effect.
The study, published in the journal Neurology, also found that about one in 16 strokes in people in the type A group is due to their blood alone.
dr Steven Kittner, professor of neurology and co-principal investigator on the study, said: “The number of people with early stroke is increasing.
“These people are more likely to die from the life-threatening event, and those who survive may face decades of disability.”
He added: “We still don’t know why type A blood carries a higher risk, but it probably has something to do with blood clotting factors like platelets and cells that line the blood vessels.”
According to official figures, there were more than 91,000 strokes in England, Wales and Northern Ireland in the 12 months between April 2021 and March 2022.
About 800,000 people in the United States suffer a stroke each year.
Almost half of Britons and Americans have type O blood and a third have type A blood.
Type B and AB account for around 10 and five percent, respectively.
dr Clare Jonas, the head of research communications and engagement at the charity Stroke Association, said the latest study is a “major step” in our understanding of the genetic risk factors for stroke.
She told The Daily Telegraph: “We don’t yet know why people with type A blood might be at increased risk of early stroke.
“This means that we are not yet able to develop targeted prevention for an early stroke.
“However, this research is a major step in helping health workers identify who would benefit most from monitoring of other risk factors and from risk reduction offerings.”
“Everyone should take steps to monitor and control their risk of stroke. The most important things you can do to reduce your risk of stroke is to monitor your blood pressure and lead a healthy and active lifestyle.”