Can your blood type affect your risk of heart disease?
A review of studies has found a link between a person’s blood type and their risk of heart disease. But the increased risk is fairly small, and there are likely to be many other more important causes of heart disease than blood types.
There are four main blood groups: A, B, AB, and O. The letters refer to which types of proteins are found in the blood. These are determined by the genes you inherit from your mother and father.
Which blood type you have can be important. If you need a blood transfusion it needs to be of the same blood type, and if you are pregnant, your blood type is tested to avoid any problems for your baby after birth.
For some years, there has also been research looking into the effect that people’s blood type might have on their chances of having heart disease. Some studies have suggested blood type can affect the proteins and other substances in the body that can cause inflammation in the blood vessels. This has been shown to be linked to an increased risk of heart disease.
But we still don’t have definite evidence, because many of the studies have been unreliable. So researchers pooled the results of two large studies. In both studies, researchers asked participants to fill in detailed questionnaires about their health, lifestyle, diet, and other health-related information, including their blood type. They then recorded how many participants developed heart disease over an average of 25 years.
In total, around 90,000 people were included in the study. Of these, more than 4,000 developed heart disease.
After taking into account other factors that might have affected people’s risk of heart disease, researchers found there was a link between blood type and heart disease risk.
Compared to people with blood type O (the most common blood type in the UK and the US, followed by A, B, and then AB), people who had blood types A, B, and AB were 11 percent more likely to develop heart disease.
When researchers looked at each individual blood type, they found people with blood type A were 6 percent more likely to develop heart disease, while people with blood type B were 15 percent more likely, and type AB were 23 percent more likely.
But overall the results suggested the effect of having a non-O (and less common) blood type on your risk of getting heart disease was low. The researchers estimated that, across a whole population, in only 6 in every 100 people with heart disease would there be a link to a non-O blood type.
How reliable is the research?
This type of study can’t prove blood type causes heart disease, although it can show a link between blood type and heart disease. The researchers did try to rule out other factors that affect heart disease, such as whether people smoked, whether they were taking medication, or how much exercise they had.
What does this mean for me?
This study suggests that, for people with less common blood types - A, B, and AB - there may be a link to an increased risk of heart disease. However, this link is not certain. If you have one of these blood types, there is nothing you can do to change it.
To provide even greater transparency and choice, we are working on a number of other cookie-related enhancements. More information