Almost half of all dementia cases could be delayed or prevented by considering 14 possible risk factors, including vision loss and high cholesterol.
This is the main finding of a new study that we and our colleagues published in the journal The Lancet.
Dementia is a rapidly growing global challenge, affecting an estimated 57 million people worldwide. This number is expected to rise to 153 million worldwide by 2050. Although the prevalence of dementia is declining in high-income countries, it continues to increase in low- and middle-income countries.
This third updated report of the Lancet Commission on Dementia contains good news and a strong message: politicians, clinicians, individuals and families can take ambitious action to prevent and reduce the risk of dementia and improve the quality of life of people with dementia and their caregivers through evidence-based approaches.
The new report confirms 12 previously identified potentially modifiable risk factors from two earlier reports published in 2017 and 2020. It also provides new evidence for two other modifiable risk factors: vision loss and high levels of low-density lipoprotein (LDL) cholesterol, often referred to as “bad” cholesterol.
Our review of published evidence found that addressing 14 modifiable risk factors overall could reduce the prevalence of dementia by 45 percent globally. Even greater risk reductions may be possible in low- and middle-income countries, and for low-income people in higher-income countries, given the prevalence of dementia, health inequalities and risk factors in these populations.
The report also suggests that reducing these 14 risks can increase the number of healthy years of life and reduce the time spent in ill health in people with dementia.
In addition, the report cites clinical studies showing that non-pharmacological approaches, such as using activities tailored to interests and abilities, can reduce dementia-related symptoms and improve quality of life.
We are general internists and applied sociologists and intervention scientists, and our work focuses on memory and well-being in older adults. Together with 25 other internationally recognized dementia experts, led by Professor of Psychiatry Dr. Gill Livingston, we carefully reviewed the evidence to derive recommendations for prevention, intervention and care.
Why it is important
The rapid growth of the world’s ageing population is a triumph of improved public and personal health across the lifespan. However, given that there is still no cure for dementia, this report highlights the importance of prevention and improving the quality of life of people with a dementia diagnosis.
In the new report, our team proposed an ambitious dementia prevention programme that could be implemented at individual, community and policy levels and across the lifespan from early to middle and late life. The key points are:
- Improving general education at a young age.
- In midlife: Treatment of hearing loss, high LDL cholesterol, depression, traumatic brain injury, physical inactivity, diabetes, smoking, high blood pressure, obesity, and excessive alcohol consumption.
- In later life, social isolation, air pollution and vision loss decrease.
Taken together, these findings lead to the Lancet Commission on Dementia’s estimate that dementia risk can be reduced by 45 percent. And a host of new research shows that tackling risk factors such as exposure to air pollution is associated with improved cognitive abilities and likely a reduction in dementia risk.
New evidence supports the idea that in high-income countries, reducing the risk of dementia may translate into more healthy years, years free of dementia, and shorter disease duration in people who develop dementia.
What is not yet known
The 45% reduction in the risk of dementia in the global population is based on a calculation that assumes that risk factors are causal and can be eliminated. It shows the importance of dementia prevention and the impact it would have on individuals and families.
The Commission stressed that more research is needed to identify additional risk factors, examine changes in risk factors in clinical trials, provide guidance for public health efforts, and identify and evaluate strategies for implementing and scaling up evidence-based programs to support people with dementia and their caregivers.
The updated report has global public health and research implications and will be widely shared, guiding clinicians and policymakers and outlining new research directions.
The Research Brief is a summary of interesting scientific papers.
Eric B. Larson, Associate Professor of Medicine, UW School of Medicine, University of Washington and Laura Gitlin, Dean Emerita and Distinguished Professor of Nursing and Health, Drexel University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
