Age is the biggest risk factor for Alzheimer’s. Approximately 10 percent of people over the age of 65 develop the disease. And for most of us, getting older is something we just can’t avoid. As global public health experts expect dementia cases to triple by 2050, scientists are racing to find ways to stop the clock on neurodegenerative diseases like Alzheimer’s, and they’ve set their sights on a small segment of the population who never experience it. They’ve taken to referring to this group as “superagers.”
First coined by scientists at Northwestern SuperAging Research Program, the term “superagers” describes people in their 80s and 90s with above-average cognitive abilities and an active social life. While it isn’t an official scientific term, it’s been very useful for the research community as they explore what might be keeping these individuals so healthy.
What is it that protects superagers from neurodegeneration?
In one recent study,scientists studied the brains of 102 deceased superagers who were all aged 97 at the time of death, and who had performed well in cognitive tests in their last year of life.
Some of these 97-year-olds did, it turned out, have the hallmark beta-aymloid plaques that appear in Alzheimer’s disease. And yet, they never developed symptoms. Here are three of the current theories as to why superagers remain resilient.
1. 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 2013 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.
2. 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.
3. Superagers are socially, mentally, 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.
Another recent study found that superagers also tend to move faster than other older people their age, irrespective of how often they exercise, and also tend to have better mental health — which could be related to their rich social lives.
There’s a “chicken and egg” aspect at work here, as staying active could preserve health, but it also takes cognitive and physical health to stay active. Still, making an effort to exercise and be social is one of those modifiable lifestyle factors that research indicates could help to protect the brain from disease.
