Abstract
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.
Generated Summary
This research investigates the association between a traditional rural dietary pattern, along with its major components (beans and rice), and all-cause mortality in elderly Costa Ricans. The study utilizes a prospective cohort design, the Costa Rican Longevity and Healthy Aging Study (CRELES), which began in 2004 and followed 2827 elderly participants (aged 60+) over a 15-year period. The study assessed dietary intake using a food frequency questionnaire (FFQ) and calculated dietary patterns through principal component analysis. The researchers employed multivariate energy-adjusted proportional-hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). The primary goal was to determine if a traditional Costa Rican dietary pattern was linked to lower mortality rates, and if so, whether specific dietary components played a significant role. The study also explored potential sex-specific differences in these associations, as well as other dietary patterns that may be associated with all-cause mortality.
Key Findings & Statistics
- Study Population: The CRELES study included 2827 elderly Costa Ricans (60+ years at baseline) who were followed for up to 15 years.
- Deaths: Over the 15-year follow-up period, there were 1667 deaths.
- Traditional Dietary Pattern: The traditional Costa Rican dietary pattern was more prevalent in rural areas.
- All-Cause Mortality and Traditional Dietary Pattern: Subjects in the fifth quintile of the traditional dietary pattern had an 18% lower all-cause mortality rate compared to those in the first quintile (HR: 0.82; 95% CI: 0.69, 0.98; P-trend = 0.01).
- Sex-Specific Analysis of Traditional Dietary Pattern: In a sex-stratified analysis, males in the third, fourth, and fifth quintiles had 26% (HR: 0.74; 95% CI: 0.56, 0.97), 28% (HR: 0.72; 95% CI: 0.55, 0.94), and 27% (HR: 0.73; 95% CI: 0.56, 0.95) lower all-cause mortality, respectively, than those in the first quintile.
- Bean Consumption and All-Cause Mortality: Bean intake was associated with lower all-cause mortality among all subjects (HR: 0.79; 95% CI: 0.68, 0.91, highest vs. lowest tertile). In the sex-stratified analysis, females in the highest tertile of bean consumption had 23% lower all-cause mortality (HR: 0.77; 95% CI: 0.62, 0.96), and males in the highest tertile saw 21% lower all-cause mortality (HR: 0.79; 95% CI: 0.63, 0.98).
- Rice Consumption and All-Cause Mortality: Rice consumption was inversely associated with all-cause mortality solely among males (HR: 0.75; 95% CI: 0.60, 0.94, highest vs. lowest tertile).
- Dietary Patterns Explained: The 4 dietary patterns explained approximately 29% of food intake variation.
- Kaiser-Meyer-Olkin (KMO) Test: The KMO test value was 0.56, indicating adequate sample size for factor analysis.
- Mortality in Quintiles: Elderly Costa Ricans in the fifth quintile of the traditional dietary pattern had an 18% lower all-cause mortality rate relative to those in the first quintile (HR: 0.82; 95% CI: 0.69, 0.98).
- Beans and Rice Consumption: Compared with the lowest tertile of bean consumption, those in the middle tertile had a 15% lower all-cause mortality rate (HR: 0.85; 95% CI: 0.75, 0.97), while the highest tertile showed a 21% lower rate (HR: 0.79; 95% CI: 0.68, 0.91).
- Rice Consumption and Mortality (Males): In sex-stratified analyses, males in the highest tertile of rice consumption had a 25% lower all-cause mortality rate (HR: 0.75; 95% CI: 0.60, 0.94) compared to the lowest.
Other Important Findings
- The traditional Costa Rican dietary pattern was characterized by high consumption of grains (mostly rice and beans) and moderate low intake of dairy products, dressings, and sweets/desserts.
- The second dietary pattern showed a moderate consumption of alcohol and soft drinks, chicken, and fried foods.
- The third dietary pattern was characterized by high use of soybean oil.
- The fourth dietary pattern was characterized by high use of spreads and moderate consumption of condiments and red meat.
- Among those with the traditional dietary pattern, the fifth quintile showed higher fiber and carbohydrate intake and less fat.
- Beans, a major component of this pattern, was also associated with lower all-cause mortality.
Limitations Noted in the Document
- The study’s reliance on a reduced FFQ may not fully capture the complexity of an individual’s diet and may not accurately measure portion sizes.
- The FFQ did not separate rice into refined and whole grains, nor did it categorize legumes into more detailed categories.
- Although the study adjusted for several potential confounders, residual and/or unmeasured confounding cannot be ruled out.
- The study acknowledges that the observed inverse association between rice consumption and all-cause mortality could be partially explained by unmeasured healthy behaviors, especially among males.
Conclusion
This study provides compelling evidence that adherence to a traditional Costa Rican dietary pattern, particularly one rich in beans, is linked to lower all-cause mortality among the elderly. The results underscore the critical role of diet in promoting healthy aging and increasing longevity within this population. The finding that males in the highest quintile of the traditional dietary pattern had a significantly lower mortality rate compared to those in the lowest quintile highlights the importance of this dietary pattern. The study emphasizes the need for the nutritional transition, a shift away from traditional diets, which could be associated with negative health outcomes and reduced longevity, particularly within the aging population of Costa Rica. The inverse association between rice consumption and all-cause mortality, particularly among males, requires further investigation, as the type of rice consumed and other lifestyle factors may influence this association. The findings have significant implications for public health, as they highlight the need to promote and preserve traditional dietary patterns, especially those that include beans, in order to mitigate the health challenges associated with an aging population and improve longevity. The study’s insights may inform strategies to improve overall health and well-being in aging populations.