Nearly half of dementia cases worldwide could be prevented or delayed, study finds, with experts citing 14 risk factors.
The number of people living with dementia worldwide is predicted to nearly triple to 153 million by 2050, with researchers warning that it poses a rapidly growing threat to health and social care systems. Research has shown that the global health and social costs associated with dementia exceed $1 trillion (£780 billion) per year.
However, the earthquake report Published in The LancetA panel of 27 of the world’s leading dementia experts concluded that many more cases could be prevented or delayed than previously thought.
By addressing 14 modifiable risk factors, starting from early childhood and throughout life, we could potentially prevent or delay 45% of dementia, even as people live longer. The Lancet Commission on Dementia The findings were presented at the Alzheimer’s Association International Conference held in the United States.
Speaking to the Guardian, Professor Jill Livingstone, lead author of the study, said it was becoming increasingly clear that there was much more that millions of people could and should do to reduce their risk of dementia.
Speaking at the Philadelphia conference, Livingston said: “Many people around the world believe dementia is inevitable, but it’s not. Our report concludes that we can significantly increase the chances of not developing dementia or delaying its onset.”
“While there is strong evidence that the longer one is exposed to risk, the greater the impact, it is important to stress that it is never too early or too late to act.”
Livingstone, of University College London, added that people at all stages of life, from children to older adults, can take steps to reduce their risk of developing the disease, which has no cure, or at least prevent it until later in life.
Based on the latest available evidence, the report adds two risk factors linked to 9% of dementia cases: Around 7% of cases are linked to high low-density lipoprotein, or “bad,” cholesterol in middle age, starting around age 40, and 2% of cases are attributable to untreated vision loss in later life.
These new risk factors are in addition to 12 identified by the Lancet commission in 2020, which together account for around 36% of dementia cases, Livingstone said.
These are: low education levels, hearing impairment, high blood pressure, smoking, obesity, depression, lack of physical activity, diabetes, excessive alcohol consumption, traumatic brain injury, air pollution and social isolation.
“The potential for prevention is high and, overall, eliminating these 14 risk factors could theoretically prevent almost half of all dementia cases. These findings are encouraging,” the experts wrote in their report.
Livingstone said there was also emerging evidence that reducing the risk of dementia not only extends healthy lifespan, but also reduces the time people who develop dementia spend in ill health.
“A healthy lifestyle such as regular exercise, smoking cessation, cognitive activity in midlife (including outside of formal education) and avoiding excessive alcohol consumption not only reduces the risk of dementia but may also delay its onset,” she said.
This means that people who develop dementia will live with it for a shorter period of time, Livingstone said, adding: “This not only has a huge impact on quality of life for individuals, but also has cost-saving benefits for society.”
Livingstone said one of the simplest things people can do to prevent the risk of dementia is to incorporate some exercise into their daily lives, such as walking or sedentary exercise, if they lead a primarily sedentary lifestyle.
To reduce the lifetime risk of dementia, the Lancet commission made 13 recommendations, including providing hearing aids to people with hearing loss, reducing exposure to harmful noise, and detecting and treating high cholesterol from around the age of 40.
Other recommendations include making testing and treatment for vision disorders available to all, providing quality education for children and promoting cognitive activity in middle age.
In another study Published in the Lancet Health and Longevity Journal The researchers worked with the committee to model the economic impact of implementing some of these recommendations, using England as an example.
Researchers found that public health interventions that tackle risk factors could save £4 billion by reducing dementia rates and helping people live longer and healthier lives.
Fiona Carragher, chief policy and research officer at the Alzheimer’s Society, which part-funded the research, said: “Some dementia risk factors can be managed through lifestyle changes, such as alcohol consumption and exercise, but many need to be addressed at a societal level.”
“Social isolation, educational disparities and air pollution are beyond individual control and require public health interventions and joint government and industry action.”
Susan Kohlhaas, research director at Alzheimer’s Research UK, which funded the study, warned that age and genetics remain the biggest risk factors for dementia.
But she said the finding that several other health and lifestyle factors are at play was “good news” because it offers a “huge opportunity” for people and governments to take preventative measures to reduce the devastating impact of dementia on society and their loved ones in the future.
