These 14 Modifiable Risk Factors Could Cut Dementia Cases By Half, Lancet Commission Finds
By Mark Moran
November 7, 2024
Article In Brief
The third Lancet Commission Report on Dementia Prevention, Intervention, and Care—the first such statement since 2020—offers an ambitious and detailed analysis of evidence emphasizing the importance of prevention. However, the commission also added two modifiable risk factors to the list, high cholesterol and vision loss, which reflects an accumulation of evidence since the previous Lancet reports.
Addressing 14 modifiable risk factors might prevent or delay nearly half of all dementia cases worldwide, even as people around the world live longer and the number of people with dementia is set to rise dramatically in all countries, according to the third Lancet Commission Report on Dementia Prevention, Intervention, and Care.
The report was published in The Lancet on July 31 in concert with a presentation of its findings at the Alzheimer’s Association International Conference. The previous Lancet Commission reports were released in 2017 and 2020.
The report is an ambitious and detailed analysis of evidence emphasizing the importance of prevention, but it also includes an analysis of evidence supporting various interventions and follow-up care for dementia. This year’s report is notable for adding two modifiable risk factors—high cholesterol and vision loss. (See “The 14 Modifiable Risk Factors for Dementia” for the entire list.)
The prevention recommendations encompass those requiring policy changes at national and international governmental levels as well as individually tailored interventions that neurologists, other physicians, and members of the public can implement.
Actions to decrease dementia risk should begin early and continue throughout life, and since risk is clustered in individuals, interventions should often be multicomponent, according to the Commission.
“There is much that physicians can do to prevent dementia,” lead author Gill Livingston, MD, professor of psychiatry of older people at University College London, told Neurology Today. “It is one of the most dreaded diseases of older people and is extremely expensive—not just in terms of providing care, but from lost productivity associated with caregiving by family members.”
She added that the effects of addressing modifiable risk factors are cumulative and will help individuals live longer, healthier lives even if they have dementia later on. “Healthy lifestyles that involve regular exercise, not smoking, cognitive activity, and avoiding excess alcohol can not only lower dementia risk but may also push back dementia onset,” Dr. Livingston said. “People are likely to have longer, healthier lives, and if they do develop dementia, they are likely to live less years with it. This has huge quality-of-life implications for individuals as well as cost-saving benefits for societies.”
The addition of high cholesterol and vision loss as modifiable risk factors reflects an accumulation of evidence since the previous Lancet reports. Since 2020, a meta-analysis of three cohort studies, all from the UK, looking at LDL cholesterol in adults younger than 65 years followed for more than 12 months reported that each 1 mmol/L increase in LDL cholesterol was associated with an 8 percent increase in incidence of all-cause dementia.
Similarly, new meta-analytic evidence implicates vision loss in the development of dementia. “The easiest ways to get cognitive stimulation is through hearing and seeing,” Dr. Livingston told Neurology Today. “With vision loss, there is a reduction in cognitive stimulation, and it may be harder for people to get out socially, and they may not be able to exercise or drive. People may not even be aware they are losing sight because it comes on gradually.”
What Clinicians Can Do
Experts who reviewed the report for Neurology Today emphasized that although several of the recommendations are broad, offering primary preventive measures directed at policymakers, there is much that individual physicians and patients can do.
“These recommendations are intended to guide public health initiatives,” said Deborah E. Barnes, PhD, MPH, professor of psychiatry and behavioral sciences and epidemiology and biostatistics at the UCSF Weill Institute for Neurosciences and Osher Center for Integrative Health at the University of California, San Francisco. “Clinicians can use these recommendations to help support their patients to make healthier lifestyle choices and to better manage risk factors. Even small changes may help lower a person’s risk of developing dementia or delay onset of symptoms.
“Neurologists can check for the 14 risk factors in this report when they are assessing patients for cognitive decline,” she said. “They can refer patients for additional care if medical risk factors are identified that are not being well-managed. For the two new risk factors, this could include making sure patients with cataracts get surgery in a timely manner and making sure high cholesterol is treated.”
She added, “New dementia medications may help some patients, but they are contraindicated for many people and have serious side effects. Prevention and risk reduction should remain the first line of defense against dementia. However, even if all 14 of these risk factors could be eliminated from our society, it would only prevent half of cases. It will still be important to identify people who develop dementia and make sure they and their families get the care they need.”
Bryan D. James, PhD, associate professor at the Rush Alzheimer’s Disease Center in Chicago, focused on the report’s consideration of when in the life course different risk factors have the most influence on the development of dementia in later life.
“Though there is substantial evidence linking these factors to dementia across many studies, there has not been consensus on most of these factors regarding what point in the life course it is most important to address them,” he said. “This has implications for the development of interventions and even designing trials to test interventions. If a factor causes dementia but if it exerts influence in midlife, then intervening on it in later life will have limited benefit.”
Dr. James noted that four of the risk factors—smoking, depression, physical inactivity, and diabetes—moved from late-life to midlife factors between the 2020 and 2024 reports. “This reflects more evidence on when these risk factors exert most influence but means that the majority of risk factors have to be intervened upon in midlife—a time when most people, and their clinicians, may not be thinking of their dementia risk decades later.”
He added, “One thing I appreciate about this report and the population attributable approach it takes is the focus on the interplay among all of these factors and the point that addressing any single one of these factors may only lead to a 1 percent, or at most 7 percent, reduction in cases of dementia, but by addressing these 14 factors as a whole, we can reduce almost half of the cases of dementia.
“That is a powerful message, and I think [it is] more effective than trying to address one factor at a time in a reductionist manner. For example, providing accessible means for people to eat healthily, maintain weight, and exercise, ideally with other people, could address many of these risk factors upstream.”
Disclosures
Dr. Livingston had no disclosures. Dr. Barnes has received payment and stock options as a scientific consultant for Together Senior Health and Linus Health.
The 14 Modifiable Risk Factors for Dementia
THE REPORT RECOMMENDS BOTH CLINICAL AND PUBLIC POLICIES:
- Ensure good-quality education is available for all and encourage cognitively stimulating activities in midlife to protect cognition.
- Make hearing aids accessible for people with hearing loss and decrease harmful noise exposure to reduce hearing loss.
- Treat depression effectively.
- Encourage use of helmets and head protection in contact sports and on bicycles.
- Encourage exercise because people who participate in sport and exercise are less likely to develop dementia.
- Reduce cigarette smoking through education, price control, and preventing smoking in public places and make smoking cessation advice accessible.
- Prevent or reduce hypertension and maintain systolic blood pressure of 130 mmHG or less from age 40 years.
- Detect and treat high low-density lipoprotein (LDL) cholesterol from midlife.
- Encourage patients to maintain a healthy weight and treat obesity as early as possible, which also helps to prevent diabetes.
- Reduce high alcohol consumption through price control and increased awareness of levels and risks of overconsumption.
- Prioritize age-friendly and supportive community environments and housing and reduce social isolation by facilitating participation in activities and living with others.
- Make screening and treatment for vision loss accessible for all.
- Reduce exposure to air pollution.
Link Up for More Information
• Livingston G, Huntley J, Liu KY, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing commission https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)01296-0/fulltext. Lancet 2024; 404(10452):572–628.
canisgallicus 