Nearly half of dementia cases could be delayed or completely prevented by addressing 14 possible risk factors, including vision loss and high cholesterol.
This is the main conclusion of a new study that we and our colleagues have published in the journal The Lancet.
Dementia, a growing global problem, affects an estimated 57 million people worldwide, and this number is expected to reach 153 million 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 from the Lancet Commission on Dementia offers good news and a strong message: policy makers, clinicians, individuals and families can be ambitious about preventing and reducing the risk of dementia; and for people with dementia and their carers, supporting their quality of life using evidence-based approaches.
The new report confirms 12 potentially modifiable risk factors previously identified in two previous reports, published in 2017 and 2020. It also offers new evidence supporting two additional 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 could reduce the prevalence of dementia by 45% globally. Even greater risk reductions may be possible in low- and middle-income countries and for low-income people in high-income countries, given the higher prevalence of dementia, health disparities, and risk factors in these populations.
The report also says that reducing these 14 risks can increase the number of years of healthy life and reduce the duration of poor health in people with dementia.
Additionally, the report cites clinical trials 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 a general internist, an applied sociologist and an intervention scientist, and our work focuses on memory and wellbeing in older people. Working with 25 other internationally renowned dementia experts, led by Professor of Psychiatry Dr Gill Livingston, we have carefully reviewed the evidence to make recommendations for prevention, intervention and care.
Why it matters
The rapid ageing of populations worldwide is a sign of improvements in public and individual health across the life course. Yet, given the lack of a cure for dementia, this report highlights the importance of prevention and improving the quality of life of people with dementia.
In the new report, our team has proposed an ambitious dementia prevention agenda that could be implemented at individual, community and policy levels and across the life course, from early to late life. Key points include:
- Early in life, improve general education.
- In middle age, hearing loss, high LDL cholesterol, depression, head injuries, physical inactivity, diabetes, smoking, high blood pressure, obesity and excessive alcohol consumption must be addressed.
- Later in life, reduced social isolation, air pollution and vision loss.
These results are consistent with estimates from the Lancet Commission on Dementia, which suggest that the risk of dementia can be reduced by 45%. A large body of recent research shows that addressing risk factors, such as exposure to air pollution, is associated with improved cognitive function and a likely reduction in the risk of dementia.
New evidence supports the idea that in high-income countries, reducing the risk of dementia can translate into more years of good health, more years free of dementia, and shorter duration of poor health for people who develop dementia.
What is still not 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 how essential dementia prevention is and the impact it would have on individuals and families.
The commission highlighted the need for further research to identify additional risk factors, test risk factor changes in clinical trials, provide guidance for public health efforts, and identify and evaluate strategies to implement and expand evidence-based programs that support people with dementia and their caregivers.
The updated report has a global impact on public health and research and is widely disseminated. It serves as a guideline for clinicians and policy makers and sets new research directions.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
