Age is the major risk factor for Alzheimer’s—approximately 10 percent of people over the age of 65 develop the disease. As cases are set to triple by 2050, scientists are racing to understand how they can stave it off. They’ve set their sight on a small group of older people who don’t experience any cognitive decline, called superagers

“Superagers” is a term first coined by scientists at Northwestern SuperAging Research Program to describe people in their 80s and 90s with superior cognitive abilities, memory, and an active social life. While it isn’t an “official” scientific term, it is very useful for researchers, allowing them to study what makes these individuals so healthy. 

One major question scientists are hoping superagers can help them answer: What is it that protects some people from neurodegenerative diseases like Alzheimer’s?

A new study published in the Journal of Alzheimer’s Disease performed an autopsy on the brains of 102 superagers, aged 97 at the time of death. Testing done two to 12 months prior to their death confirmed the superagers were still cognitively sharp. 

Despite many having the hallmark beta-amyloid plaques, the superagers never developed Alzheimer’s.

Future studies may reveal why superagers remain resilient. It’s a “chicken and egg” question, as it takes cognitive and physical health to stay active, but making an effort to exercise and be social is one of those modifiable lifestyle factors that could very well help to stave off cognitive decline.

Superagers’ brains don’t gradually shrink as much as other people’s brains do

The superagers’ brain may be resilient to Alzheimer’s because it appears to shrink slower. In fact, one part of the brain might not shrink at all in superagers. 

The researchers of a 2012 study at Northwestern University compared the brains of 12 so-called superagers to 10 cognitively normal older individuals between the ages of 50 and 65. What they found was that the superagers group had a fundamental structural difference in the cingulate cortex, a region of the brain important for memory, attention, cognitive control, and motivation was larger in superagers. 

Since the cingulate cortex is important for many of the cognitive functions that are impaired in Alzheimer’s, researchers think it might be why superagers are resilient. It begs the question whether figuring out how to stop the cingulate cortex from shrinkage could be a key to helping prevent age-related memory loss down the road.

Superagers have a lot of mysterious, giant von Economo neurons

A third superpower of super-agers brains? They seem to have three to five times the amount of a certain, mysterious neuron called the von Economo neuron than other people. 

These specialized neurons may die off over the course of mild cognitive impairment and Alzheimer’s disease. Scientists believe von Economo neurons are involved in complex cognitive functions. 

Superagers are socially and physically active — and that might protect their brain health 

Because superagers lead rich social lives well into their 80s and 90s, and studies show that mental and physical activities—like cooking or dance classes—keep the brain active, it’s possible these things might all be interconnected. 

This tendency to be socially and intellectually engaged might even play a role, some scientists think, in stimulating the cingulate cortex and the von Economo neurons.