A new study published in Neurology, the medical journal of the American Academy of Neurology, reports older adults with anemia have an increased risk of developing dementia.
Anemia is a condition where red blood cells don't carry enough oxygen to the rest of the body. A lack of iron is a common cause of anemia.
The study followed about 2,500 participants in their 70s. The data collection began in 1997. Participants were initially tested for anemia and cognitive function and underwent testing over the next decade.
Researchers found that people who had anemia at the beginning of the study had a 41 percent higher risk of developing dementia than those who were not anemic.
The study is not yet definitive, according to Leilani Doty, co-director of the University of Florida Cognitive and Memory Disorder Clinics.
"This is not saying that anemia causes dementia," she said. "It's saying that anemia is of interest to follow and to look at when people have concerns of memory changes."
Some hypotheses from the study to explain the link to dementia include chronic brain hypoxia associated with anemia, anemia due to chronic kidney disease, anemia due to deficiency of micronutrients, and perhaps anemia as a marker of poor health.
Dr. Doty says anemia may be linked to dementia under the "cardiovascular dementia" category, which is affected by things such as control of diabetes, blood pressure, or cholesterol.
"Further research and looking maybe in more detail — at the anemia, at the lifestyles of the people, at interventions — would definitely be of value," she said.