Low levels of red blood cells, otherwise referred to as anemia, could increase the risk of dementia, according to a recent study published on July 31 in an online issue of the medical journal Neurology.

“Anemia is common in the elderly and occurs in up to 23 percent of adults ages 65 and older,” says study author Dr. Kristine Yaffe from the University of California – San Francisco and member of the American Academy of Neurology. “The condition has also been linked in studies to an increased risk of early death.”

The study included 2,552 adults between the ages of 70 and 79. Each participant was tested for anemia and underwent thinking and memory tests for an 11 year period. Of the study participants, 393 had anemia at the beginning of the study. By the time the study was concluded, 445 participants had developed dementia. This number accounts for about 18 percent of the total number of participants involved.

What the research found was that people who had anemia at the beginning of the study had about a 41 percent higher risk of developing dementia than those who did not. The link between the two remained even after considering other factors, such as age, race, sex and education. Of the 393 participants with anemia, 89 of them, about 23 percent, developed dementia compared to the 366, or 17 percent, of 2,159 participants that did not have anemia when the study began.

“There are several explanations for why anemia may be linked to dementia. For example, anemia may be a marker for poor health in general, or low oxygen levels resulting from anemia may play a role in the connection. Reductions in oxygen to the brain have been shown to reduce memory and thinking abilities and may contribute to damage to neurons,” Yaffe says.

The study received support from the National Institute on Aging and the American Health Assistance Foundation.