Community Health Workers Could Help Prevent Dementia, but Cognitive Health Is Being Left Behind

Community health workers—the trusted local laypeople who deliver health education and chronic disease support in underserved communities—may represent one of the most underused weapons in the fight against dementia. That is the central conclusion of a systematic review published in Trends in Psychology, in which researchers from Brazilian universities analyzed 35 studies of community health worker–led interventions targeting modifiable risk factors for dementia in adults aged 60 and older. The review, led by Bruna Luísa de Souza Pereira of the Federal University of Minas Gerais, paints a picture of genuine promise shadowed by a striking blind spot: almost none of the existing programs directly address cognitive health itself.

The scale of the potential opportunity is hard to overstate. Dementia affects tens of millions of people worldwide, and the World Health Organization has declared 2021 to 2030 the Decade of Healthy Ageing as populations gray at an unprecedented pace. Yet a substantial share of dementia risk appears to be modifiable. The Lancet Commission on dementia prevention has estimated that addressing risk factors such as hypertension, diabetes, obesity, physical inactivity, smoking, depression, and low social engagement could prevent or delay a meaningful proportion of cases. Epidemiological modeling by Barnes and Yaffe, cited in the review, similarly projected that reductions in risk factor prevalence could substantially lower Alzheimer’s disease prevalence. In other words, the biological pathways that lead to cognitive decline run, in part, through conditions that community-level interventions can reach.

This is precisely where community health workers enter the picture. Also known as promotoras, lay health educators, or community health agents, these workers are typically drawn from the communities they serve, sharing language, culture, and lived experience with the people they visit. The American Public Health Association defines them by this frontline, trusted-member role, and the International Labour Organization classifies them as a distinct occupational category. Their model is perhaps most institutionalized in Brazil, where community health agents form the backbone of the national primary care system under the Unified Health System, making regular home visits to families in their territories. The Brazilian policy framework, revised in 2017 under the National Primary Care Policy, formally embeds these workers in preventive care.

To map what these workers have actually been doing in relation to dementia risk, the research team searched five major databases—Medline, SciELO, PsycINFO, Web of Science, and Scopus—for studies published between January 2000 and October 2021. They applied the PRISMA 2020 reporting guidelines for systematic reviews and included only studies that evaluated community health worker training or interventions aimed at people aged 60 or older. The initial search retrieved 4,370 articles, which the team screened using the Rayyan web application, with study selection and data extraction performed independently and inter-rater agreement assessed using the standard Landis and Koch thresholds. After the full screening process, 35 studies met the inclusion criteria.

The dominant finding was unmistakable: the overwhelming majority of interventions targeted cardiovascular and metabolic risk factors, chiefly hypertension, diabetes, and obesity. These are not arbitrary choices. Midlife hypertension is one of the most robust modifiable predictors of later dementia, and type 2 diabetes and obesity are both independently associated with elevated cognitive decline risk through vascular and metabolic mechanisms. The reviewed studies spanned an impressive geographic and cultural range. In rural India, a cluster randomized controlled trial led by Gamage and colleagues tested a scalable group-based education and monitoring program delivered by health workers to improve blood pressure control. In Nepal, the COBIN trial evaluated female community health volunteers leading a lifestyle intervention for blood pressure reduction. In rural Mexico, a stepped-wedge analysis examined a community health worker program for diabetes and hypertension. In Argentina, a hypertension control program delivered with community workers was subjected to trial-based cost-effectiveness analysis.

Diabetes prevention and management featured especially prominently, particularly in programs serving Latino, African American, Asian American, and Native Hawaiian and Pacific Islander communities in the United States. Studies such as the DIALBEST trial, which showed improvements in blood glucose control among Latinos with type 2 diabetes, the HELP PD trial translating the Diabetes Prevention Program into community settings with lay educators, and randomized trials among Korean, Vietnamese, and Hispanic populations demonstrated that lay workers can achieve measurable improvements in hemoglobin A1c, weight, physical activity, and dietary behaviors. Other studies examined weight-loss interventions translated into senior centers by lay health educators, falls prevention exercise programs delivered by community care workers, physical activity promotion during home visits by Brazilian community agents, and even smoking cessation support, another recognized dementia risk factor.

Yet when the researchers looked specifically for interventions aimed at cognitive stimulation or cognitive training—the direct exercise of memory, attention, and executive functions—they found almost nothing. Only one of the 35 included studies specifically addressed cognitive stimulation. This is a remarkable gap given that meta-analyses of memory training and cognitive training in older adults, including work by Gross and colleagues and by Kelly and colleagues, suggest that structured cognitive practice can improve trained cognitive domains, and that frequent cognitive activity may compensate for educational disadvantages in episodic memory. The review’s authors argue that this absence reveals a field anchored almost entirely in a biomedical model of chronic disease management, in which community health workers are deployed as extensions of clinical care for hypertension and diabetes rather than as promoters of brain health in its own right.

The biomedical anchoring has a second, subtler cost: the neglect of sociocultural context. Although community health workers are prized precisely for their cultural proximity and territorial bonds, the review found that few studies incorporated the sociocultural realities of the communities they served into intervention design. The authors suggest that public policies and training programs that genuinely value these territorial relationships and invest in educational practices could expand what community health workers are able to do. Instead of simply checking blood pressure readings and reinforcing medication adherence, workers could be equipped to engage older adults in conversations about cognitive engagement, social participation, and lifestyle patterns that shape long-term brain health—dimensions that the Lancet Commission identifies as part of the dementia prevention portfolio.

The implications for health equity are significant. Dementia risk is not evenly distributed: low-income populations carry a disproportionate burden of untreated hypertension, uncontrolled diabetes, and limited access to preventive care, and they are also less likely to reach specialized memory clinics. Community health workers operate exactly where these risks concentrate. The evidence reviewed suggests they can contribute to dementia prevention, particularly in low-income settings, by addressing the modifiable conditions—vascular and metabolic—that feed into cognitive decline. If the vascular and metabolic health of midlife and older adulthood shapes dementia risk decades later, then a workforce capable of delivering affordable, culturally attuned chronic disease support at scale is, functionally, a dementia prevention workforce, whether or not it describes itself that way.

The review’s authors are careful about the limits of the evidence. The included studies varied widely in design, outcomes, and quality, and the field lacks trials that follow community health worker–led programs all the way to cognitive outcomes, let alone dementia incidence. The authors call for future research to prioritize cognitive-focused interventions and to specify the training components that make community health workers effective, so that their capacity can be optimized rather than assumed. As global aging accelerates and dementia cases climb, the review’s message is both encouraging and cautionary: the community workforce needed for prevention largely already exists and has proven it can move the metabolic and cardiovascular needles—but almost no one has yet asked it to protect the brain directly. Closing that gap, the authors argue, will require deliberate policy choices, better training, and a research agenda that treats cognitive health not as a specialty concern but as a community one.

Subject of Research: Community health worker–led interventions targeting modifiable dementia risk factors in older adults

Article Title: Community Health Worker–Led Interventions Targeting Modifiable Risk Factors for Dementia in Older Adults: A Systematic Review

Article References: de Souza Pereira, B. L., dos Santos, L. A., Barroso, S. M., & Mansur-Alves, M. (2025). Community Health Worker–Led Interventions Targeting Modifiable Risk Factors for Dementia in Older Adults: A Systematic Review. Trends in Psychology. https://doi.org/10.1007/s43076-025-00493-5

Image Credits: AI Generated

DOI: 10.1007/s43076-025-00493-5

Keywords: community health workers, dementia prevention, modifiable risk factors, older adults, hypertension, diabetes, obesity, cognitive stimulation, systematic review, primary health care, health equity, cognitive aging