Why do some elderly people not suffer from dementia?

0

Researchers may have discovered a key reason why some people stay sharp in their 80s and 90s: their brains resist the accumulation of certain proteins that mark Alzheimer's disease.

The study focused on what scientists called “superheroes” – a select group of older people who have a memory several decades younger. The researchers found that compared to older adults with average brain power, the superheroes had much less evidence of “tau tangles” in their brains.

Tau is a protein that helps stabilize the internal structure of healthy brain cells. But abnormal versions of tau can also develop – those that cling to other tau proteins. In people with Alzheimer's, the brain is marked by large accumulations of these tau tangles, as well as “plaques,” which are clumps of another protein called amyloid.

For years, amyloid plaques have attracted the most attention as a potential target for Alzheimer's treatment. , said researcher Tamar Gefen, who led the new study.

But a body of evidence suggests otherwise: It is the accumulation of tau — not amyloid — that correlates with declines in memory and thinking skills, said Gefen, an associate professor at the School of Medicine. Feinberg at Northwestern University in Chicago.

This study involved people age 80 and older. But other studies, Sexton said, have narrowed their focus to unusually sharp 90-year-olds or even long-lived people. The million-dollar question: What does it take to become a member of this elite group?

According to Sexton, superheroes probably have genetics to thank in part.

But it's likely, she says. , it's a combination of good genes, lifestyle factors, and lifelong influences, from physical activity to social activity and mental stimulation.