"The lesson is that to have a healthy brain when you're 70, you need to eat right and exercise when you're 50," said study coauthor Elizabeth Selvin, PhD, MPH, Associate Professor of Epidemiology and Medicine, Welch Center for Prevention, Epidemiology and Clinical Research and the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
The researchers found that diabetes appears to age the mind roughly 5 years faster beyond the normal effects of aging. "For example, on average, a 60-year-old with diabetes experiences cognitive decline on par with a healthy 65-year-old aging normally. Persons with diabetes with poor glucose control were at particularly high risk for cognitive decline," Dr. Selvin explained.
The researchers followed 13,351 adults (24% black; 76% white) age 48 to 67 years (mean age at the start of the study, 57 years) living in 4 communities in Maryland, North Carolina, Minnesota, and Mississippi.
Participants completed tests of cognitive function (or mental processes) between 1990 and 1992 and again approximately 6 and 20 years later.
Diabetes Linked To Greater Cognitive Decline
Participants with diabetes had a 19% greater decrease in scores on cognitive function tests compared with people without diabetes. The results were the same for both white and black participants. Similarly, people with prediabetes (people at risk for diabetes because of higher than normal blood sugar levels) also had a greater risk for cognitive decline.
In addition, the risk for cognitive decline was greatest among people with poorly controlled diabetes or who had diabetes for a longer time.
"We know that even weight loss of 5% to 10% of body weight can be significant for prevention of diabetes. If we can prevent diabetes and [help achieve] better control glucose in persons with diabetes, we may be able to prevent or delay cognitive decline in old age," Dr. Selvin said.
January 14, 2015
Rawlings AM, Sharrett AR, Schneider AL, et al. Diabetes in midlife and cognitive change over 20 years: a cohort study. Ann Intern Med. 2014;161(11):785-793.