Elderly people with cardiovascular disease showed sharper declines in cognitive function over a four-year period than their peers with healthy hearts, Dr. Snorri Bjorn Rafnsson of the University of Edinburgh and colleagues found.

While there is currently no way to prevent Alzheimer's disease, it may be possible to ward off so-called vascular dementia, another leading cause of mental impairment in aging people. As Rafnsson told Reuters Health, the findings offer "some kind of hope that this type of problem can be controlled and contained in an ever-growing population."

Doctors have typically thought of vascular dementia as a consequence of suffering multiple strokes, but evidence is mounting that other types of cardiovascular disease may also take their toll on cognitive function, Rafnsson and his colleagues note in the journal Psychosomatic Medicine.

To better understand the relationship between various types of heart and blood vessel disease and mental function, the researchers followed 452 elderly individuals for four years, over a third of whom had at least one type of cardiovascular disease --such as angina, stroke or intermittent claudication, or reduced blood flow in the legs due to hardening of the arteries.

Individuals who had suffered a stroke during the follow-up period had a significantly greater decline in verbal memory performance than those who had not, while people with peripheral artery disease -- meaning blood vessel disease in regions other than the heart or brain -- also showed steeper-than-average drops in cognitive function. The results held true even after the researchers accounted for other factors related to both heart disease and mental function, such as depression.

It's likely, Rafnsson said in an interview, that the factors that are contributing to atherosclerosis are also involved in mental decline. Reductions in blood flow due to atherosclerosis in the blood vessels feeding the brain -- as well as those within the brain itself -- may be gradually eroding cognitive function.

Doctors should monitor patients with cardiovascular disease for cognitive decline, he added, while any therapies that can help "contain the progress of atherosclerosis" -- for example, statins for high cholesterol -- are likely to help prevent mental decline as well.

"Anything that leads to better cardiovascular health, more favorable levels of cardiovascular risk factors, blood pressure, cholesterol, not to smoke -- these are all likely to impact the brain, the blood flow to the brain, arterial function, and eventually cognitive function."