'People With Type A Blood Group At Higher Risk Of Stroke': What Study Says

If you have type A blood group, you are at an increased risk of suffering from a stroke before you turn 60.

(Photo: iStock/Altered by FIT)

If you have one of the type A blood groups (type A or type AB), you have a 16 percent higher chance of suffering from a stroke before you turn 60 compared to people with other types of blood groups.

A study, titled Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke, published in the Neurology journal last year, suggests so. 

Here’s all you need to know about the study.

The Big News: After going through data collected from over 6 lakh people (18-59 age group), out of whom 17,000 had suffered a stroke, the researchers claim to have established a direct correlation between the presence of the “gene for the A1 subgroup and early-onset stroke.”

“The study found that people with early stroke were more likely to have blood type A and less likely to have blood type O (the most common blood type) -- compared to people with late stroke and people who never had a stroke. Both early and late stroke were also more likely to have blood type B compared to controls.”

Study- Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke

What Stats Show: According to the study, while those with one of the type A blood groups have a 16 percent higher chance of stroke, those with the gene for O1 type have a 12 percent lower chance of suffering from a stroke.

On the other hand, people who have the type B blood group are at an 11 percent increased risk of stroke, irrelevant of age.

Interestingly, the study also found that in people who had suffered a stroke before the age of 60, the leading causes included the building up of fatty deposits in their arteries and clot formations. And for people with type A blood group who suffered a stroke after the age of 60, the significance of the gene wasn’t noteworthy.

Cause For Concern? Not yet. In a news release, the study’s co-principal investigator and a neurologist at the University of Maryland Medical Center, Steven J Kittner, said,

“We still don’t know why blood type A would confer a higher risk, but it likely has something to do with blood-clotting factors like platelets and cells that line the blood vessels as well as other circulating proteins, all of which play a role in the development of blood clots. We clearly need more follow-up studies to clarify the mechanisms of increased stroke risk.”

He advised that since the risk is modest, there’s no need for people to “engage in extra screening or medical testing based on this finding.”

However, according to ScienceAlert, the type A and type B genomic sequences are infamous for a “slightly higher risk of blood clots in veins” and are “associated with coronary artery calcification.”

The Limitations: 65 percent people involved in the study were of European ancestry, which means that the sample involved in the study lacked diversity. The data was compiled from the Early Onset Stroke Consortium, which included data from studies conducted in North America, Europe, Japan, Pakistan, and Australia.

The news release read:

“About 35 percent of the participants were of non-European ancestry.”