Dementia rates are going down. That’s even though dementia risk factors like diabetes are rising. What’s behind the decline in dementia? Dr. Ken Langa, associate director of the Institute of Gerontology at the University of Michigan, says higher levels of education and better treatment of diseases that lead to dementia could have a lot to do with it.
Langa’s research program has tracked 20,000 older adults since the early 1990s. Among adults over 65, dementia dropped from 11.6% to 8.8% between 2000 and 2012. While any decline in dementia is certainly a good thing, said Langa, this “relatively large” change is especially encouraging. These findings mirror similar studies in other high-income countries, he said, indicating a larger trend.
Although scientists are glad to see the decline, these numbers also open up a larger question: Why is this happening?
One possibility is education. Langa notes that the older adults in this study are among the first age cohort to benefit from changes in public policy that expanded access to schooling. Compared to the older adults studied in 2000, the 2012 group had almost an extra year, on average, in the classroom. While Langa cautions that “the brain is a complicated organ,” this correlation may indicate that the more the brain exercises, the healthier it stays. In scientific terms, education might increase “cognitive reserve,” which builds and strengthens brain wiring, and ultimately help brains compensate for aging.
Another factor, says Langa, is that “there’s a close connection between the heart and the brain.” While high blood pressure, high cholesterol, and diabetes are not declining, they are being treated more actively. When patients get treatment for heart problems, the effects can be passed on to the brain. Today’s older adults may be more likely to be engaged in physical activity, not smoking, and eating a balanced diet than those from the previous decade, and that might mean a decrease in dementia.
Of course, more study is needed to understand these links better. Decreasing heart risk and education are almost certainly good for your brain, but Langa cautions that he “can’t say that we have the final word” about how they prevent dementia. Even though schooling does seem to be a factor, scientists haven’t yet figured out the “active ingredient” in protecting against memory loss, and whether those benefits could transfer to other activities, such as employment. Regardless, Langa and his team are encouraged by the decline, and hope future research brings more answers – and good news.
Listen to the full interview above to hear more about the study and what the future may hold for this research.