Traditional rural dietary pattern and all-cause mortality in a prospective cohort study of elderly Costa Ricans: the Costa Rican Longevity and Healthy Aging Study (CRELES).

BACKGROUND: Costa Rica is experiencing a fast demographic aging. Healthy diets may help to ameliorate the burden of aging-related conditions. OBJECTIVE: This study aimed to investigate the association of a traditional dietary pattern and 2 of its major components (beans and rice) with all-cause mortality among elderly Costa Ricans. METHODS: The Costa Rican Longevity and Healthy Aging Study (CRELES), a prospective cohort study of 2827 elderly Costa Ricans (60+ y at baseline), started in 2004. We used a food frequency questionnaire (FFQ) to assess usual diet. We calculated dietary patterns using principal component analysis. Multivariate energy-adjusted proportional-hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Over a 15-y follow-up, encompassing 24,304 person-years, 1667 deaths occurred. The traditional Costa Rican dietary pattern was more frequent in rural parts of the country, and it was inversely associated with all-cause mortality. Subjects in the fifth quintile of intake had 18% lower all-cause mortality than those in the first quintile (HR: 0.82; 95% CI: 0.69, 0.98; P-trend = 0.01), particularly among males (HR: 0.73; 95% CI: 0.56, 0.95). Bean intake was associated with lower all-cause mortality among all subjects (HR: 0.79; 95% CI: 0.68, 0.91, highest compared with lowest tertile) and in sex-stratified analysis. Rice consumption was inversely associated with all-cause mortality solely among males (HR: 0.75; 95% CI: 0.60, 0.94, highest compared with lowest tertile). CONCLUSIONS: Our results suggest that a traditional Costa Rican rural dietary pattern is associated with lower all-cause mortality in elderly Costa Ricans. Beans, a major component of this traditional dietary pattern, was also associated with lower all-cause mortality. These findings could have important implications for public health, given the nutritional transition and the reduction of intake of traditional diets in Latin American countries.

Frailty as a predictor of mortality: a comparative cohort study of older adults in Costa Rica and the United States.

BACKGROUND: Frailty is a common condition among older adults that results from aging-related declines in multiple systems. Frailty increases older adults' vulnerability to negative health outcomes, including loss of mobility, falls, hospitalizations, and mortality. The aim of this study is to examine the association between frailty and mortality in older adults from Costa Rica and the United States. METHODS: This prospective cohort study uses secondary nationally-representative data of community-dwelling older adults from the Costa Rican Longevity and Healthy Aging Study (CRELES, n = 1,790) and the National Health & Aging Trends Study (NHATS, n = 6,680). Frailty status was assessed using Physical Frailty Phenotype, which includes the following five criteria: shrinking, exhaustion, low physical activity, muscle weakness, and slow gait. We used Cox proportional hazard models to examine the association between frailty and all-cause mortality, including sociodemographic characteristics and health behaviors as covariates in the models. Mortality follow-up time was right censored at 8 years from the date at baseline interview. RESULTS: The death hazard for frail compared to non-frail older adults was three-fold in Costa Rica (HR = 3.14, 95% CI: 2.13-4.62) and four-fold in the White US (HR = 4.02, 95% CI: 3.04-5.32). Older age, being male, and smoking increased mortality risk in both countries. High education was a protective factor in the US, whereas being married/in union was a protective factor in Costa Rica. In the US, White older adults had a lower risk of death compared to all other races and ethnicities. CONCLUSIONS: Results indicate that frailty can have a differential impact on mortality depending on the country. Access to universal health care across the life course in Costa Rica and higher levels of stress and social isolation in the US may explain differences observed in end-of-life trajectories among frail older adults.