Lifestyle affects the brain as well as the heart

There is growing evidence that what's good for the heart is also a boon for the aging brain, according to a new research review.

In a survey of 26 large studies of older adults, an expert panel found that certain heart-health factors - like high blood pressure, diabetes and exercise habits - appeared key to study participants' cognitive function as well.

Cognitive function refers to a person's ability to learn, reason and remember, for example, and these skills commonly decline with age. In some cases, the decline is part of a process leading to Alzheimer's disease or other forms of dementia.

But a growing number of studies are finding that controllable lifestyle factors such as exercise and intellectual and social engagement throughout life seem to alter a person's risk of cognitive decline and dementia.

Going out for a daily walk might not prevent Alzheimer's, but it might help delay its onset, according to Dr. Hugh C. Hendrie of the Indiana University Center for Aging Research in Indianapolis.

Hendrie headed the committee that conducted the research review, which is published in the Alzheimer's Association journal Alzheimer's & Dementia.

The review included 96 analyses of 26 North American and European studies that followed large groups of older adults over time, charting both cognitive and emotional health.

What emerged was an unexpected level of consistency regarding some risk factors, according to Hendrie.

"It did surprise us a little that there's some consensus developing," he told Reuters Health.

Among the consistent findings were the associations between high blood pressure and poorer cognitive function and between regular exercise and sharper cognitive skills. A number of studies have also implicated diabetes and excess weight in contributing to age-related cognitive decline.

The reasons for all these associations are not completely clear, Hendrie said, but damage to blood vessels - either to large vessels from a major injury like a stroke, or to smaller vessels from the long-term build-up of plaques - may offer one explanation.

So the same things recommended for heart health - including moderate exercise, a healthy diet, and preventing or controlling conditions like high blood pressure and diabetes - may protect mental health as well, according to Hendrie and his colleagues.

Regarding exercise, animal research suggests it may even have direct protective effects on brain cells, Hendrie pointed out. "It does look like exercise is important," he said.

Though it's not clear how much exercise is necessary, moderate activity like walking is a good idea for overall health - and, Hendrie noted, "it's never too late for older people to start."

Mental exercise may also be key, a number of studies show. Older adults who stay intellectually stimulated through reading or other hobbies may slow the onset of cognitive decline, and the same may be true of people who stay socially active.