This 2-year single-blind RCT across 11 Latin American countries tested whether a culturally adapted, structured multidomain lifestyle intervention (SLI: diet, exercise, cognitive training, vascular risk management) outperformed a flexible lifestyle intervention (FLI: general health advice) on global cognitive function and trial feasibility in 1,065 adults aged 60–77 with elevated dementia risk.
Global cognitive composite scores improved significantly more in the SLI group vs. FLI group (mean annual gain: 0.31 SD vs. 0.20 SD; between-group difference 0.11 SD/year, 95% CI 0.06–0.15; p<0.0001). Trial feasibility was supported: recruitment effectiveness 62%, SLI adherence 71.6%, and 2-year follow-up completion 82.3% overall. Adverse events were more frequent in the SLI group (412 vs. 66), mostly musculoskeletal symptoms; no deaths were intervention-related.
- No active placebo in the FLI arm; differential contact time may inflate the apparent benefit of SLI. - Practice effects likely contributed to cognitive score gains in both groups, complicating interpretation of true prevention. - Higher dropout in the FLI group (20.2% vs. 15.2%) could bias between-group comparisons despite blinded outcome assessment.
Clinicians managing older adults at high dementia risk in Latin America can consider structured multidomain lifestyle programs (combining exercise, diet, cognitive training, and vascular risk management) as a feasible, scalable strategy to slow cognitive decline. Musculoskeletal safety monitoring should be built into any physical activity component.
