There's a way to possibly reduce the risk of dementia or cognitive impairment, or lessen its impact if it strikes, and it doesn't involve taking a pill.

The medical journal Mayo Clinic Proceedings recently published a review of the literature to see if there was any evidence of its theory that exercise can help fight dementia. After looking at 1,600 papers, it reported that, yes, aerobic exercise "significantly reduced" the risk of dementia and reduced the risk of mild cognitive impairment. Additionally, exercise helped to slow the diseases after it started.

It doesn't happen overnight, of course. In one study, it took 6 to 12 months for the test results to show up, but the literature showed that participants had better spatial memory and slower loss of brain matter. In another study, brain scans (MRI) showed better "connectivity," meaning that the pathways in the brain improved. Even more, exercise was associated with a slowing of dementia caused by small blood vessel disease.

What does this mean for us? It means that aerobic exercise, or anything that gets the heart pumping and increases the need for oxygen, results in better blood flow to the brain. Brain pathways stay open and cognitive abilities are preserved or improved.

Aerobic exercise, however, doesn't necessarily mean we need to work out at the gym. Daily walks at a rate that pumps up the heart rate a bit, swimming, seated workouts and senior fitness classes can all help.

More studies need to be done, but the review of all that literature indicates that we're on the right track if we exercise. Ask your doctor before you start anything new.