Blood Type May Influence Dementia Risk

People with the least common blood type may have a higher risk of dementia than those with other types, a new study suggests. The study included more than 30,000 people, ages 45 or older. They were given a series of tests of memory and thinking skills. About 500 people had low enough scores to show some impairment. Researchers compared the blood types of this group with almost 600 people who had normal test scores. People with type AB blood were 82% more likely to have impaired thinking skills than those with type O blood. Only 4% of people in the study had type AB blood. O is the most common type. Researchers said the increased risk for those with type AB was relatively small. Smoking, lack of exercise and obesity are linked with much greater risks of dementia. The journal Neurology published the study online. HealthDay News wrote about it September 10.