Healthy Diet, Exercise Keeps Mind Sharp As You Age

July 15 -- TUESDAY, July 14 (HealthDay News) -- Eat right, exercise and hope that your genes don't predispose you to dementia.

That's the recipe for preserving cognitive function as you age, according to four new studies that were presented this week at the Alzheimer's Association annual meeting, in Vienna.

The findings echo other research suggesting that clean living can safeguard mental sharpness. However, one of the studies did contain a surprise finding -- that strenuous exercise actually impaired cognitive skills later in life.

That should be viewed, for now, with some skepticism, said William Thies, chief medical and scientific officer of the Alzheimer's Association.

"That's something I wouldn't take on faith from a single study," he stressed.

But the heart-healthy diet advice seemed sound, he said, and confirms other research. In that study, Heidi Wengreen, an assistant professor of nutrition at Utah State University, asked 3,831 adults, aged 65 and older, to complete a food survey. They then tested their cognitive skills over an 11-year period, beginning in 1995.

The researchers looked to see how well the participants followed the DASH diet, an eating regimen that protects against hypertension and heart trouble. Those who followed the DASH diet more closely had higher scores on the cognitive tests at the start of the study and over time, Wengreen found.

Although Wengreen said more study was needed, "I believe there is plenty of evidence to suggest that diet plays a role in delaying cognitive decline and perhaps preventing Alzheimer's disease among the elderly."

Two exercise studies found staying active can also help.

In one study, Deborah E. Barnes, of the University of California, San Francisco, followed more than 3,000 adults aged 70 to 79. Those who were sedentary had the lowest level of cognitive function at the start and higher rates of decline over the course of the seven-year study.