The number of adults (aged 40 years and older) living with dementia worldwide is expected to nearly triple, from an estimated 57 million in 2019 to 153 million in 2050, due primarily to population growth and population ageing.
The Global Burden of Disease study is the first to provide forecasting estimates for 204 countries worldwide, and is published in The Lancet Public Health.
The study also looks at four risk factors for dementia—smoking, obesity, high blood sugar, and low education—and highlights the impact they will have on future trends.
For example, improvements in global education access are projected to reduce dementia prevalence by 6 million cases worldwide by 2050.
But this will be countered by anticipated trends in obesity, high blood sugar, and smoking, which are expected to result in an additional 6·8 million dementia cases.
Dementia is currently the seventh leading cause of death worldwide and one of the major causes of disability and dependency among older people globally—with global costs in 2019 estimated at more than US$1 trillion.
Although dementia mainly affects older people, it is not an inevitable consequence of ageing.
A Lancet Commission published in 2020 suggested that up to 40% of dementia cases could be prevented or delayed if exposure to 12 known risk factors were eliminated—low education, high blood pressure, hearing impairment, smoking, midlife obesity, depression, physical inactivity, diabetes, social isolation, excessive alcohol consumption, head injury, and air pollution.