Which Blood Type Increases Your Risk of Dementia?

Science has identified several risk factors for dementia including smoking, high blood pressure, genetics, diabetes and more. But one study suggests that your blood type may also influence your risk for cognitive problems, affecting memory, word-finding, personality, and more.

close-up of doctor placing blood vial in rack
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Risk Factors

A team of researchers studied more than 30,000 people over the course of a 3 1/2 year period. During the study, the participants' cognitive functioning was tested to determine if any decline was present. Researchers used tests that measured verbal fluency, immediate memory, orientation, and ability to learn a 10-word list.

At the end of the study period, significant cognitive decline had developed in 495 people. Of this group, researchers found that one particular blood type demonstrated a higher risk for cognitive decline: the type of blood known as AB. Additionally, higher levels of factor VIII- a protein that facilitates clotting of blood- were also correlated with a greater risk of cognitive problems.

How Many People Have the AB Blood Type?

AB blood is quite rare. According to the American Red Cross, about 4 percent of Caucasians, 4.3 percent of African-Americans, 2.2 percent of Hispanic Americans and 7.1 percent of Asian Americans have AB blood.

Why Is the Risk Higher?

One theorized reason by the study's authors why blood type AB is correlated with a higher risk of cognitive impairment is that this blood type is also more highly connected to cardiovascular problems, and research has already demonstrated a tie between heart problems and cognitive decline. Additionally, risk of cardiovascular disease is increased by some of the same risk factors that are tied to a higher risk of dementia, including obesity and diabetes.

What Should You Do if You Have AB Blood?

First, remember that this is only a single study, and it needs to be replicated to determine if the same results occur in other research.

Also, although this study does show a correlation (note that it does not prove that one causes the other) between blood type and risk of cognitive decline, research has demonstrated that there are many other factors that have shown to be associated with a reduced risk of dementia. In other words, there are many things that you CAN control that reduce your dementia risk. Diet, physical exercise, and mental activity all have repeatedly been correlated with reduced risk of dementia.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Alexander, Kristine S., Zakai, Neil A., Gillett, Sarah, McClure, Leslie A., Wadley, Virginia, Unverzagt, Fred, and Cushman, Marry. "ABO Blood Type, Factor VIII, and Incident Cognitive Impairment in the REGARDS Cohort." Neurology. September 30, 2014 vol. 83 no. 14 1271-1276.
  • American Red Cross. Blood Types.

By Esther Heerema, MSW
Esther Heerema, MSW, shares practical tips gained from working with hundreds of people whose lives are touched by Alzheimer's disease and other kinds of dementia.