Key points from article :
Some older folks are still sharp as tacks and dementia-free well into their 80s and beyond.
German researchers have uncovered: Their genes may help fend off protein build-up in the brain.
Super agers scored highest on memory tests, brain protein profiles similar to healthy folks who were much younger.
"Super aging refers to exceptionally high cognitive functionality, even when you turn 80 or 90 years old," - Merle Hoenig, lead researcher.
Abnormal build-up of tau and plaques are considered a warning sign for impaired thinking.
A Colombian woman with high risk for Alzheimer's disease had only mild dementia when she died at age 77 of cancer.
Rare genetic mutation appeared to protect her from a similarly large build-up of tau tangles.
"Super agers do not appear to accumulate aging-associated proteins, such as tau and amyloid pathology," - Hoenig.
Study didn't examine the effects of lifestyle choices and more research is needed.
Research by University of Cologne published in JAMA Network Open.
