Kristine Yaffe, MD, and colleagues of the Health ABC Study examined more than 2,500 people aged 70 to 79 over 11 years. None of them had dementia at baseline, and 15 percent had anemia.
Study participants underwent memory and thinking tests. During the investigation period, 18 percent of all study participants developed dementia. Those who had anemia at the start of the study had a 41 percent higher risk of developing dementia than those who were not anemic. The association between anemia and dementia remained even after investigators adjusted for age, race, sex and education, and the association still was significant after they adjusted for the presence of other medical conditions and other signs of red blood cell health.
Anemia and dementia may be linked, Yaffe said, because anemia may be a sign of poor health in general. Also, low oxygen levels that stem from anemia may result in neuron damage and reduced memory and thinking abilities, she said.
The authors call for further research into the association between anemia and dementia and for study into how anemia might someday be treated as a way to improve cognitive health.
Yaffe, who was senior author of the study, is a professor at the University of California, San Francisco. Other institutions involved in the study were the San Francisco Veterans Affairs Medical Center, the Ajou University School of Medicine in Korea, the University of Tennessee Health Science Center, the University of Pittsburgh, the University of Washington and the National Institute of Aging.