While dieting is one of those issues we need to keep an eye on throughout our lives, there are other factors that become more important as time goes on.

For seniors, good health means more than just watching what you eat. It means staying sharp. The latest research shows there are four things you can do to help keep that mental edge.

A study published in the June issue of Neurology followed 2,500 people aged 70-79 over eight years, giving them cognitive tests during that period.

The researchers found that roughly half of the seniors had the normal, expected decline during that time. Around 16 percent showed a more significant decline.

But nearly a third – 30 percent – showed no change at all. Some in that group even appeared to grow sharper.

How’d they manage that? Researchers found four key differences in these sharper seniors: exercise, education, not smoking and socializing.

And these are all good areas to focus on.

In the study, researchers found that seniors who got moderate-to-vigorous exercise at least once a week were 30 percent more likely to hold on to their mental skills.

I don’t think anyone needs to be running marathons, especially if you’re 79 years old. But find something you enjoy that gets your muscles moving and your blood pumping, even if it’s just a regular walk through the park at a steady pace.

Education – at least, formal education – is probably something you can’t change much at this point in your life. In this study, researchers found that folks with at least a high school education were three times more likely to stay sharp.

But there’s a larger point here that’s a little harder to measure, and that’s the importance of learning, no matter how old you are. Whether you read a book or attend a senior class at the local college, I believe you can help yourself stay sharp by continually making your mind do some real work.

I never advocate smoking, and here’s another reason to kick the habit: non-smokers were twice as likely to hold onto their mental skills as smokers.

Finally, the researchers zeroed in on something we’ve talked about plenty in recent months: socializing.

We’ve known all along that seniors who keep active socially have a better chance of living longer and warding off age-related conditions like dementia.

And researchers in this latest study found that seniors who volunteered, worked or even just lived with someone else were 24 percent more likely to stay sharp than those who don’t.

These researchers didn’t seem to consider the role of diet, but good nutrition is important at any age. If you fail to eat well, you risk not only gaining weight, but also losing focus and energy if you deprive yourself of key nutrients.

If you’re older, keep these tips in mind.

But even if you’re not, these are all great habits, whether you’re 17 or 71. Enjoy them now, and enjoy them even more later in life, when these habits help you live better in your golden years.