Because the hippocampus has many layers, it’s possible the calcification didn’t damage the layers involved in memory, de Brouwer said. More research is needed to explore possible links between calcifications and cognitive problems, the study authors conclude.
Participants in the study were 78 years old on average, although they ranged in age from 45 to 96.
Each added year of age was associated with a five percent greater risk of calcification in the hippocampus, the study found.
Overall, 228 participants, or about 12 percent, were smokers. Once researchers accounted for factors like age, sex, high blood pressure, high cholesterol, and diabetes, the smokers in the study were 49 percent more likely to have calcifications in the hippocampus than nonsmokers.
A total of 317 participants, or about 16 percent, had diabetes. After researchers accounted for smoking status and the other factors they examined for smokers, they found diabetics were 50 percent more likely to have calcifications than participants without diabetes.
The study wasn’t designed to prove whether or how smoking or diabetes might directly contribute to calcifications in the hippocampus or cognitive problems.
Even though the study didn’t connect calcifications to worse cognitive abilities, calcium may accumulate more when people have unhealthy blood vessels, said Dr. Rebecca Gottesman, a neurology researcher at Johns Hopkins University in Baltimore who wasn’t involved in the study.
“This study did suggest that the more risk factors you have, the more hippocampal calcification you have,” Gottesman said by email. “And, other studies have suggested that a greater number of these types of risk factors can be associated with worse cognitive outcomes.”