According to a recent report from the (US) National Academies of Sciences, Engineering and Medicine, there is really no good proof that we know of anything you can do to lower your risk of cognitive decline with age.
That’s the depressingly bad news.
The more optimistic slant is that there are good hints that exercise, controlling blood pressure, and perhaps even the oft-maligned brain-training exercises might help.
I’m willing to bet that exercise and appropriate BP control help your brain although I have strong doubts about the benefits of brain training.
But one caveat: an expert who commented on this report was quoted as saying that even if they don’t eventually help your brain, at least these interventions “do no harm”.
I would strongly argue with that wording, however.
There is definitely significant potential harm from BP control (side effects and complications from the drugs used especially when there’s an emphasis on very tight control of BP, as increasingly common) and there is often harm from exercise (especially injuries) although I do agree that the overall benefits from sensible use of these lifestyle interventions are very likely to outweigh the potential downsides.
As ever, be smart – moderation, moderation, moderation – and you’re likely to stay smart.