Well, I don't know if we'll be able to reverse brain aging anytime soon, but we at least know some ways of slowing it down, like by language learning or some other mental tasks.

I personally recommend at least giving a try for learning a new foreign language, it's fascinating journey and even it might be hard at first it's very satisfying in the end. And some people might say that it's not worth it because of AI, but come on, you can still do it for fun, and bigger cultural understanding.