Changes to lifestyle may avert dementia
Up to a third of the world’s dementia cases could be prevented by addressing factors such as education, hypertension and diet, according to a new report presented at the Alzheimer’s Association International Conference in London.
The report was compiled by the first Lancet Commission on Dementia Prevention and Care, which brought together 24 experts from across the globe to review scores of studies and synthesise them into a model showing how lifestyle modification could reduce dementia risk.
About 47 million people worldwide have dementia – a figure that is projected to triple by 2050.
The report identifies nine risk factors, including years of education before age 15; hypertension, hearing loss and obesity in middle age; as well as smoking, depression, physical inactivity, social isolation and the late onset of diabetes.
The Lancet team calculated whether modifying each factor could potentially affect a person’s dementia risk.
Over the past decade, research has increasingly pointed to controllable lifestyle factors as being integral to stalling cognitive decline. Scientists believe that, as with heart disease, combating dementia is likely to require a ‘‘cocktail’’ approach of drugs and lifestyle changes.
‘‘The message is that conditions like
Reducing the risk of dementia by 35 per cent with lifestyle modification is "far larger than anything you can ever expect for drugs". Lancet report co-author Lon Schneider
dementia are not immutable and are substantially modifiable by the environment,’’ said Lon Schneider, a professor of psychiatry and behavioural sciences at the University of Southern California’s Keck School of Medicine and a co-author of the Lancet report.
Noting that modifying all nine factors could reduce the risk by 35 per cent, he said: ‘‘Compare that to how we’re developing drugs to treat dementia. Dementia is not a condition that’s ever going to be such that a single drug can be considered a cure for the illness.’’
Lifestyle modification was inexpensive, and the proposed reduction was ‘‘far larger than anything you can ever expect for drugs’’, he said.
Last month, a report by the National Academies of Sciences, Engineering and Medicine took a more cautious approach to the effects of lifestyle modification, finding that evidence of their efficacy when derived from randomised controlled trials ‘‘remains relatively limited and has significant shortcomings’’.
This report, which used different methodologies to the Lancet Commission’s, found just three types of intervention offered ‘‘encouraging but inconclusive’’ evidence: cognitive training; blood pressure management for hypertension; and increased physical exercise.
Ronald C Petersen, director of the Mayo Clinic Alzheimer’s Disease Research Centre and the Mayo Clinic Study of Ageing, presented that report at this week’s conference. He said large trials that were ongoing or forthcoming could provide more evidence to support the effects of lifestyle intervention.
One such study was announced at the British gathering: in 2018, the Alzheimer’s Association plans to launch a $27 million, two-year clinical trial to see if lifestyle improvements can prevent cognitive decline.
The United States Pointer project will work with 2500 older adults at risk of cognitive decline. It will test whether two years of intervention – physical exercise, nutritional counselling, social and cognitive stimulation, as well as better selfmanagement – can help brain function in participants aged 60 to 79.
Similar studies are also being conducted in Singapore and Australia. – The Washington Post