There is a group of people that longevity researchers call "SuperAgers," who are in their 80s and beyond, but have the cognitive function of those decades younger.

Conversely, it's possible for your brain to be older than your chronological age, which is what we want to avoid.

As a neuroscience researcher and author of "The Age-Proof Brain," I've found that it's our behaviors, not just our genes, that have a powerful impact on our brain's destiny.  

So what sets SuperAgers apart from people who have weak memory skills? According to a 2021 study that followed SuperAgers over the course of 18 months, one key differentiator was that they kept learning new things throughout their life.

SuperAgers learn something new every day

Think of the brain like a bank account. We make "deposits" — or new connections between our brain cells — by learning. Our memories are housed in these connections.

As we age, we naturally lose some of those connections. It's like making a withdrawal every year. But the more deposits we make throughout our lives, the less our net worth is affected by these withdrawals.

One study found that adults with more years of education had more active frontal lobes when they took memory tests. Activity in the frontal lobe is associated with better memory.

But higher education isn't the only way to maintain memory. In another study, even if individuals had lower levels of education, if they attended lectures, read, wrote and read often, they had memory scores on par with those with more education.

Which types of learning are best for brain health?

Keeping your brain healthy is not all about Sudoku, Wordle or crossword puzzles. Those can have cognitive benefits, but you are mostly exercising with the knowledge and skills you already have.

What does make significantly new connections in the brain is learning new skills and information. And the process should be challenging: SuperAgers embrace — and sometimes crave — that feeling of frustration when they learn something outside of their expertise.

'Cross-train' your brain

Approach learning the way you would with fitness training. You wouldn't go to the gym and only work out your forearms. Eventually, you would look like Popeye.

The same goes for the brain. Learning a new language, for example, works out different parts of the brain than a new sport or instrument does.

You can cross-train your brain by mixing mental and physical learning activities. Get out your calendar and plan different types of activities using this plan:

• Day 1: Learn something mentally stimulating, such as listening to a podcast or taking an online course.
• Day 2:  Do something that requires learning through movement, such as a new sport, dance or yoga pose.
• Day 3:  Be social. Grab coffee with a friend or go to a dinner party. Yes, social interaction is a form of learning that has been associated with staving off dementia.

No matter what it is, learning new things keeps your brain young. So if you discovered something you didn't know before from reading this article, you're already helping your brain age at a slower pace.

Marc Milstein, PhD, is a brain health expert and author of "The Age-Proof Brain: New Strategies to Improve Memory, Protect Immunity, and Fight Off Dementia." He earned both his PhD in Biological Chemistry and his Bachelor of Science in Molecular, Cellular, and Developmental Biology from UCLA, and has conducted research on genetics, cancer biology and neuroscience. Follow him on Twitter and Instagram.

Don't miss:

• A neuroscientist shares the brain exercise she does for a stronger memory — and the mistake that can ‘harm’ it
• A Harvard nutritionist shares the 6 best brain foods: ‘Most people aren’t eating enough of’ these
• A Harvard nutritionist shares the No. 1 vitamin that keeps her brain 'young and healthy'—and foods she eats 'every day'

Want to earn more and work less? Register for the free CNBC Make It: Your Money virtual event on Dec. 13 at 12 p.m. ET.

Sign up now: Get smarter about your money and career with our weekly newsletter