Population-level interventions for dementia risk factors
Dementia is a neuro-degenerative condition resulting in cognitive and physical decline over time. In the early stage of the condition, physical decline may be slow, but in the later stages, it may become more pronounced. Physical interventions may be employed to try and reduce the physical decline that people experience, yet it is unclear what interventions may be effective.
Global population aging is mirrored by an increase in the prevalence of dementia, with estimates suggesting an increase from 76 million people living with dementia in 2024 to 153 million by 2050. In 2020, there had been several modifiable risk factors for dementia, including lower education levels, depression, and physical inactivity, and updated in 2024 adds untreated vision loss, and high LDL (low-density lipoprotein) cholesterol as further risk factors. Although disease-modifying treatments are starting to emerge, prevention strategies targeting risk factors are paramount.
Strategies to reduce dementia risk by tackling risk factors has primarily taken the form of individual-level interventions. However, these type of interventions unduly place the burden of prevention on individuals and therefore long-term efficacy and adherence are contingent on individuals’ willingness to participate, ongoing motivation, and personal resources. Results from trials of multidomain interventions to prevent cognitive decline, show that adherence decreases with greater intervention complexity and intensity.
Despite dementia being a global public health concern, population-level interventions remain under-prioritised in both research and policy. However, these interventions have been shown to be cost-effective. A recent study shows that various population-level interventions to mitigate dementia risk factors in England are highly cost-effective; for example, low emission zones in cities to lower air pollution could save $352 million, and reductions to sugar content in food to address obesity could save $1.422 billion.
Population-level interventions can overcome limitations inherent to individual-level interventions. As population-level interventions are not reliant on individuals’ active participation, challenges regarding adherence and compliance are circumvented. However, these interventions can also combat inequities in dementia prevalence by ensuring all people are given the opportunity for risk reduction. Many risk factors, such as smoking and obesity, are more common in lower socioeconomic brackets, and these disparities manifest in early life, largely driven by lower access to education and poorer living conditions.
It is therefore essential that policies target these populations to attenuate disparities. Population-level interventions are also able to reduce risk across the entire life span. Risk profiles are dynamic over the life course, with some risk factors, such as obesity, having greater impacts on dementia risk in midlife than later life, and other factors such as air pollution have greater weight in later life. Preventative approaches must therefore target at-risk populations at critical life stages.
Our increasing understanding of risk factors for dementia must be matched with efforts to mitigate these risks. Population-level interventions involve extensive effort and resources and require collaborations across various sections, including national and local governments, industry, and education. However, these interventions are likely to be cost-effective and play a pivotal role in tackling the exponential increases in dementia rates and the socioeconomic inequities of this burden. So, the development of disease-modifying treatments for dementia has made impressive advancements, and now all the people should all the governments to recognize the severity of this public health concern by devoting resources to preventative interventions, both at the individual and at the population level, to mitigate dementia risk in a cost-effective and, most importantly, equitable manner.