Targeting risk factors from childhood can cut dementia cases by one-third
Around one in three cases of dementia can potentially be prevented by modifying risk factors from as early as childhood, a recent study has shown.
The study modelled the impact of nine health and lifestyle risk factors for dementia at various stages in life. These risk factors were less education in early life; hearing loss, hypertension and obesity in mid-life; and smoking, depression, physical inactivity, social isolation and diabetes in later life. [Lancet 2017, doi: 10.1016/S0140-6736(17)31363-6]
“Although dementia is diagnosed later in life, brain changes usually begin to develop years before, with dementia risk factors occurring throughout the whole life,” said study lead author Professor Gill Livingston of the University College London, UK. “A broader approach to the prevention of dementia that reflects these changing risk factors will benefit our ageing societies and help prevent the rising number of dementia cases globally.”
Based on their results, the researchers estimated that 35 percent of dementia cases could be prevented by completely eliminating the nine modifiable risk factors. In comparison, finding a treatment that targets the apolipoprotein E ε4 allele, a major genetic risk factor of dementia, would prevent only 7 percent of the cases.
Among the nine risk factors, reducing hearing loss in mid-life (9 percent), increasing education in early life (8 percent) and smoking cessation in later life (5 percent) were the most effective ways to prevent dementia. These were followed by preventing depression (4 percent), increasing physical activity (3 percent), improving social life (2 percent), and reducing hypertension (2 percent), diabetes (1 percent) and obesity (1 percent).
“The recognition of hearing loss as a risk factor for dementia is relatively new. This has not been included in previous estimations, nor has it been a priority in the management of those at risk of cognitive impairment,” wrote the study authors. “Hearing loss might either add to the cognitive load of a vulnerable individual leading to changes in the brain, or lead to social disengagement or depression and accelerated atrophy, all of which could contribute to accelerated cognitive decline.”
The study was conducted by 24 international experts from the Lancet Commission on Dementia Prevention, Intervention, and Care, who met to consolidate currently available evidence for the prevention and management of dementia.
“We call on all governments to tackle the impending dementia crisis by generating updated action plans, drawing on the latest evidence, and incorporating awareness strategies and public health campaigns for dementia,” wrote Helen Frankish and Richard Horton from The Lancet, in an accompanying editorial. [Lancet 2017, doi: 10.1016/S0140-6736(17)31756-7] “This Lancet Commission will help inform the development and implementation of these strategies.”
“Although it is not feasible to address all potentially modifiable cases of dementia, delaying the age of dementia onset would bring enormous benefits, with estimates suggesting that a 1-year delay in onset could prevent more than 9 million cases of dementia by 2050,” they added.