Dr. Joseph M. Perlman Advanced Plastic Surgery Centre

Having the least common blood type is linked with a higher risk of memory loss. In a new study, researchers have discovered that people with type AB blood are at an 82-percent higher risk of cognitive decline.

Led by Mary Cushman, the research group gathered over 1,000 participants aged 45 or older and asked them to undergo a series of cognitive and memory tests. Afterward, blood samples were taken from each participant. For about three years, the researchers followed the patients and discovered that those with type AB blood were more likely to suffer memory loss problems later in life.

This is not the first time that this blood type has been linked with vascular problems. In a previous study, Ms. Cushman and her team also discovered that type AB people are also at an 83 percent higher risk of strokes compared to people with type O blood. In previous studies, type O blood was associated with a lower chance of developing cardiovascular disorders.

According to Ms. Cushman, the link between blood type AB and memory loss (as well as stroke) may be rooted in coagulation factor VIII, a type of blood-clotting protein.

“We think that people with higher factor VIII are at increased risk of vascular conditions, like stroke,” Ms. Cushman explained. “Since factor VIII levels are closely linked to blood type, this may be one causal connection between blood type and cognitive impairment.”

There is another physiological factor that suggests a link between cognitive functioning and blood type – ABO glycosyltransferase. It is a type of enzyme that regulates various bodily functions.

Should people with type AB blood worry about their impending memory decline? Ms. Cushman says no; at least, not yet.

“The association we saw was relatively small, and the findings need to be confirmed in other studies,” she added.