How to Prevent Dementia: Managing Smoking, Hearing Loss and Depression Can Ward off Condition

Report finds a third of dementia cases can be prevented by lifestyle factors. AFP/Getty Images

People can reduce their risk of developing dementia by effectively managing certain lifestyle and health factors, such as smoking, obesity and depression.

In a report published in the Lancet, an international team of scientists found that up to a third of dementia cases across the globe could be prevented through non-pharmacological interventions, such as exercise, social contact and weight management. The findings were presented at the Alzheimer's Association International Conference.

Dementia is not a specific disease. Instead, it describes a set of symptoms that includes memory loss, problems with problem solving and/or language and difficulties thinking. Dementia is caused by diseases like Alzheimer's, which is the most common cause of the condition.

In the U.S. alone, there are thought to be five million people living with age-related dementia. Globally, the figure is thought to be 47 million. With an aging population, this figure is expected to reach 115 million by 2050.

"There's been a great deal of focus on developing medicines to prevent dementia, including Alzheimer's disease. But we can't lose sight of the real major advances we've already made in treating dementia, including preventive approaches," Lon Schneider, a member of the Lancet Commission on Dementia Prevention and Care, said in a statement.

In the report, the team of 24 experts review existing research on dementia, including treatment and prevention strategies. They found nine risk factors, beginning in childhood, that increase the risk of developing dementia.

Preventing these risk factors begins in childhood and continues throughout life. This includes increasing education, addressing hearing loss, and managing hypertension and obesity. Combined, these factors add up to a 20 percent risk reduction. As adults get older, they can reduce the risk by a further 15 percent by stopping smoking, increasing physical activity and social contact, and managing diabetes and depression.

Schneider said: "The potential magnitude of the effect on dementia of reducing these risk factors is larger than we could ever imagine the effect that current, experimental medications could have. Mitigating risk factors provides us a powerful way to reduce the global burden of dementia."

The report also looks at how non-pharmacological interventions with people already living with dementia—such as social contact and activities—have an important role in treatment, being superior to medications in reducing agitation and aggression that can emerge as a result of the condition.

"The 2015 global cost of dementia was estimated to be $818 billion, and this figure will continue to increase as the number of people with dementia rises," the report said. "Nearly 85 percent of costs are related to family and social, rather than medical, care. It might be that new medical care in the future, including public health measures, could replace and possibly reduce some of this cost.

In a related comment piece, Martin Prince, from the Institute of Psychiatry, Psychology and Neuroscience at King's College London, U.K., said the report provides "timely evidence-driven contribution to global efforts to improve the lives of people with dementia and their carers."

"The message that dementia, alongside heart disease, stroke, and cancer can be prevented through effective implementation of public health strategies is one that policy makers and public need to hear, and act on. Nevertheless, caution is indicated. Current Alzheimer's Disease International projections assume that the age-specific dementia prevalence worldwide will remain constant over time, and prudent policy makers should plan accordingly. More research is needed, in more settings, over longer periods to estimate trends more precisely, and their regional variation."