Maintaining a healthy heart won't just keep you alive for longer – it could also be a great defence against developing dementia and cognitive decline, according to a new study.

To examine the links between cardiovascular health and the kinds of brain deterioration that come with dementia, scientists looked at data on almost 3,000 people to see if there were any positive effects on the brain when adhering to the American Heart Association's (AHA) 'ideal cardiovascular health' (CVH) index, which includes eating a balanced diet, being active, managing your weight, eliminating tobacco smoke, and maintaining ideal levels of blood sugar, cholesterol, and blood pressure.

Good ideas all round, to be sure, and according to the AHA, hitting these targets is associated with lower rates of cardiovascular disease. But now researchers think they could also help ward off dementia, cognitive decline, and stroke risk.

When examining data from 3,000 patients in the Framingham Heart Study Offspring Cohort study, scientists from Swinburne University of Technology in Australia and Boston University found that participants with higher ideal CVH scores in the study had a lower 10-year risk of developing stroke and vascular dementia.

And to some extent, the protective effects are long-lasting. Participants who previously had had higher ideal CVH also had a lower risk of developing Alzheimer's disease (AD) – which could mean that good midlife vascular health may be an important factor to help protect against developing dementia when you get older.

Over a follow-up period of seven years, participants with better CVH scores also demonstrated less brain shrinkage and less decline in mental ability. Taken together, the findings, reported in Stroke, suggest that maintaining good cardiovascular health is a win-win for heart and brain.

Of course, what we have so far is only an association between the CVH scores and cognitive decline – scientists have yet to prove causation through some kind of biological mechanism. But it's a promising line of research, especially since maintaining good cardiovascular health is something we should all be doing anyway.

"[T]here is cause for optimism, with emerging evidence suggesting that society can both grow older and lower dementia burden," the authors write. "In line with this notion, our data suggest that adhering to CVH guidelines protects against all forms of vascular brain injury, lessening the burden of cognitive decline, stroke, brain atrophy, and dementia, including AD. Further promoting ideal CVH, particularly to middle-aged adults, may improve neurological outcomes for our ageing citizens."

"The risk of dementia doubles every five years after the age of 65. With increasing life expectancies, there is a pressing need to find ways to prevent dementia," added neurologist Matthew Pase from Swinburne's Centre for Human Psychopharmacology. "Our study suggests that adhering to simple healthy heart guidelines, particularly in midlife, can significantly reduce the risk of vascular brain injury and dementia."

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