If you need more incentive to exercise more and eat better, consider the results of two comprehensive new studies that found that an active and healthy lifestyle may be critical in helping to keep the brain healthy in old age. Regular exercise, a healthy diet, keeping weight down, not smoking and moderating alcohol consumption were all linked to a lower risk of dementia. And in those with dementia, exercise improved memory and helped people stay independent longer, a rigorous review of past studies found.
In one study, researchers at the Cardiff University School of Medicine in Wales analyzed data from 2,235 Welsh men living in a small town in South Wales. All were in their 40s or 50s at the start of the study, and their progress was followed over the course of 35 years.
The researchers found that those men who followed four out of five healthy behaviors – getting regular exercise, not smoking, keeping their weight down, eating a healthy diet, and moderating alcohol intake – were 60 percent less likely to develop Alzheimer's and other forms of dementia in old age than those who followed none of these healthy lifestyle measures. Exercise had the largest impact on preserving memory and thinking skills over time.
In addition to protecting brain health, these healthy lifestyle measures reduced the risk of diabetes, heart disease and stroke by 70 percent. All of those medical conditions are known to increase the risk of memory problems and dementia.
"The size of reduction in the instance of disease owing to these simple healthy steps has really amazed us and is of enormous importance in an aging population," said Peter Elwood, the lead researcher. "What the research shows is that following a healthy lifestyle confers surprisingly large benefits to health. Healthy behaviors have a far more beneficial effect than any medical treatment or preventative procedure."
Dr. Elwood noted that if the men had been encouraged to adopt just one additional healthy behavior in middle age, and only half of them followed through, they would have shown a 13 percent overall reduction in dementia risk.
A growing body of evidence shows that what's good for the heart is good for the brain. These findings, which involved a large number of people over many years, add more evidence to show that healthy habits can reduce dementia risk.
A second comprehensive review of numerous studies conducted through a collaboration of researchers adds more evidence that exercise benefits the brain. The researchers, part of the Cochrane Collaboration, analyzed data from more than a dozen rigorous studies involving hundreds of people with Alzheimer's and other forms of dementia. Some were living at home, and others in nursing homes and other facilities.
They found evidence that exercise benefits older people with dementia by improving their memory and thinking skills. Exercise also enhanced dementia patients' ability to carry out everyday activities like walking short distances or getting up from a chair, though it did not improve symptoms of depression or mood.
"Following this new review, we are now able to conclude that there is promising evidence for exercise programs improving cognition and the ability to carry out daily activities," said Dorothy Forbes, a study leader and an associate professor of nursing at the University of Alberta. "However, we do still need to be cautious about how we interpret these findings."
"Further research is needed to be able to develop best practice guidelines to enable healthcare providers to advise people with dementia living at home or in institutions," she added. "We also need to understand what level and intensity of exercise is beneficial for someone with dementia."
Many factors are involved in who gets dementia in old age, including genetics and other facets of health. Exercise, diet and other lifestyle factors are not a cure for Alzheimer's, but they may help people stay mentally sharper longer and delay the progression of dementia symptoms, a growing body of evidence shows. As one Alzheimer's researcher put it, "Healthy living is the best revenge."
Sources: Peter Elwood, Julieta Galante, Janet Pickering, et al: " Healthy Lifestyles Reduce the Incidence of Chronic Diseases and Dementia: Evidence from the Caerphilly Cohort Study." PLoS One, Dec. 9, 2013.
Dorothy Forbes, Emily J Thiessen, Catherine M Blake, et al: "Exercise Programs for People With Dementia." Cochrane Dementia and Cognitive Improvement Group, Dec. 4, 2013.