A new study says the number of people suffering from dementia will triple by the year 2050 without interventions that address the risk factors underlying the devastating deterioration of cognitive function.
The research, published in The Lancet Public Health, projects that global cases of the condition among people 40 years of age or older will jump from an estimated 57 million in 2019, to 153 million by 2050. The sweeping study, which forecasts dementia prevalence in 204 countries, estimates Canada will have over 1.3 million cases by that time, up from around 600,000 in 2019. And while much of the increase will be driven by population growth and aging, the study says targeting four key risk factors — obesity, smoking, high blood pressure and low education — can help reduce this growing burden.
“We need to focus more on prevention and control of risk factors before they result in dementia,” said Emma Nichols, lead author of the study from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington. “Even modest advances in preventing dementia or delaying its progression would pay remarkable dividends. To have the greatest impact, we need to reduce exposure to the leading risk factors in each country.
“For most, this means scaling up locally appropriate, low-cost programs that support healthier diets, more exercise, quitting smoking and better access to education. And it also means continuing to invest in research to identify effective treatments to stop, slow or prevent dementia.”
Dementia is an umbrella term used to describe a range of cognitive issues — such as memory loss and difficulty thinking or problem solving — that are significant enough to interfere with daily life. It is projected that the total annual healthcare costs for Canadians with dementia will rise to $16.6-billion by 2031, according to the Alzheimer Society, double the total cost from 2011.
While there is no cure for dementia, research commissioned by the Lancet in 2020 found that 40 per cent of cases could be prevented or postponed by eliminating exposure to 12 known risk factors — the four mentioned above, in addition to hearing impairment, depression, physical inactivity, diabetes, social isolation, excessive alcohol consumption, head injury and air pollution.
According to the current study, prevalence of the condition divided unequally between sexes, with women with dementia outnumbering men with dementia 100 to 69 — a pattern projected to persist in the future.
“It’s not just because women tend to live longer,” said Jaimie Steinmetz, co-author of the study. “There is evidence of sex differences in the biological mechanisms that underlie dementia. It’s been suggested that Alzheimer’s disease may spread differently in the brains of women than in men and several genetic risk factors seem related to the disease risk by sex.”
The authors acknowledged a few limitations of their analysis, including a lack of high-quality data in some areas of the world and the use of some studies with differing methodologies and definitions of dementia. The study also dealt with the overall prevalence of dementia and noted that some clinical subtypes, such as vascular dementia, might not share the same relationship with known risks — a factor that could affect results. Still, researchers are sounding the alarm about the urgency of making difficult changes now, while they can still make a difference.
“Low- and middle-income countries in particular should implement national policies now that can mitigate dementia risk factors for the future, such as prioritizing education and healthy lifestyles,” said Theo Vos, co-author of the study. “Ensuring that structural inequalities in access to health and social care services can be addressed and that services can additionally be adapted to the unprecedented needs of an increasing older population with complex care needs will require considerable planning at both local and national levels.”
Dave Yasvinski is a writer with Healthing.ca