Policy and lifestyle interventions to address 14 risk factors for dementia could significantly curb the neurocognitive disorder’s global burden.
ADVERTISEMENTAddressing 14 lifetime risk factors could prevent or delay nearly half of the world’s dementia cases, which now tally 55 million, according to a group of 27 dementia experts worldwide.
Dementia has no known cure, and increasing life expectancy means the number of cases is expected to surge to 139 million by 2050, according to Alzheimer’s Disease International.
That means disease prevention and delay are key to improving older adults’ health and well-being, with the best outlook if efforts to curb these risk factors start early in childhood and reach all segments of the population.
For the first time, high cholesterol and vision loss were included in the risk factors cited by the Lancet Commission on dementia prevention, intervention, and care, the group of experts who reviewed the latest evidence on the neurocognitive disorder. Their findings were last updated in 2020.
An estimated 7 per cent of dementia cases are attributable to poor cholesterol in midlife, beginning around age 40, while two per cent of cases are tied to untreated vision loss later in life.
The other 12 risk factors include lower education levels, hearing impairment, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption, traumatic brain injury, air pollution, and social isolation in old age.
Together, they account for 40 per cent of all dementia cases worldwide, with hearing impairment, lower education levels, and social isolation having the biggest impact, the experts said.
These risks are often “clustered,” with individual people experiencing several of these factors at once, they found. Long-term exposure throughout life can also increase dementia risk.
“Our new report reveals that there is much more that can and should be done to reduce the risk of dementia,” Gill Livingston, the study’s lead author and a professor of psychiatry of older people at University College London (UCL), said in a statement.
“It’s never too early or too late to take action, with opportunities to make an impact at any stage of life”.
Researchers who were not involved with the study noted that while the findings are promising, it’s still unclear exactly how certain risk factors, such as high blood pressure, are tied to dementia.
“Our evidence base also may be inadequate to capture other important influences on dementia, such as very early life influences (e.g. brain development in utero or in adolescence) and the role of reproductive health,” Dr Sarah-Naomi James, a senior research fellow at UCL’s MRC Unit for Lifelong Health and Ageing, said in a statement. She was not involved with the report.
The Lancet commission offered both policy and individual actions to curb dementia risk.
For example, experts recommend that high-quality education be widely accessible, that people in midlife get enough mental stimulation, that people cut out smoking and excessive drinking, and that they exercise regularly and wear helmets when cycling.
“These findings highlight the intersection of daily habits and long-term brain health, emphasising that comprehensive, lifelong health strategies from early years – to be led by individuals and supported by government policies – can significantly impact dementia prevention,” Sandrine Thuret, a professor of neuroscience at King’s College London, said in a statement. She was not involved with the report.
ADVERTISEMENTLivingston said government support is particularly important to reduce dementia inequalities for low-income countries and socioeconomically disadvantaged groups.
Using England as an example, Livingston and other co-authors estimated that population-level interventions to address six dementia risk factors – smoking, excessive drinking, high blood pressure, obesity, air pollution, and head injuries – could save more than £4 billion (€4.7 billion) in health care, social, and caregiving costs.
