Did you know that your brain starts to slow down as early as your 30s?

It’s true! Research suggests that certain aspects of cognitive function (memory, processing, etc.) actually start to decline in early middle age. It’s minor and we don’t notice, partly because we get wiser as the years go by. But later in life that cognitive decline can lead to real problems, and even dementia.

So, what’s the “state of the evidence” on how to protect your brain against cognitive decline and dementia? Well, unfortunately, it’s not super encouraging. The National Institute on Aging recently commissioned a task force to review all of the scientific studies that have addressed this question. Their report is published here, and the institute director has a nice summary of it here.

The bottom line? This committee of experts basically found that there isn’t very good evidence for anything. They do point out that there is “encouraging but inconclusive” evidence for exercise, cognitive training (think brain games), and keeping blood pressure low—but it’s still a somewhat gloomy conclusion, right?

Maybe, but to be clear, when scientists and doctors review evidence like this, they are looking for bulletproof data showing that something works. The best kind is from randomized controlled trials, in which researchers test the effects of something like exercise against no exercise (or some other control condition). As you can probably imagine, it’s hard to do a long trial like this in which you follow people over time, years maybe, and check to see if their cognitive function declines. So, that’s partly why the evidence is inconclusive—scientists just haven’t done enough trials like this.

What does it mean? Well, preventing cognitive decline and dementia is one of the hottest research topics these days, so there’s sure to be more info on this in the near future (and we’ll keep you posted). In the meantime, the evidence for the protective effects of exercise, some dietary factors, and even a bit of a mental workout, is generally positive (if not bulletproof)—and these things are good for you anyway, so maybe think about adding them to your daily routine.