Adherence to a healthy diet according to the World Health Organization guidelines and all-cause mortality in elderly adults from Europe and the United States

Abstract

The World Health Organization (WHO) has formulated guidelines for a healthy diet to prevent chronic diseases and postpone death worldwide. Our objective was to investigate the association between the WHO guidelines, measured using the Healthy Diet Indicator (HDI), and all-cause mortality in elderly men and women from Europe and the United States. We analyzed data from 396,391 participants (42% women) in 11 prospective cohort studies who were 60 years of age or older at enrollment (in 1988-2005). HDI scores were based on 6 nutrients and 1 food group and ranged from 0 (least healthy diet) to 70 (healthiest diet). Adjusted cohort-specific hazard ratios were derived by using Cox proportional hazards regression and subsequently pooled using random-effects meta-analysis. During 4,497,957 person-years of follow-up, 84,978 deaths occurred. Median HDI scores ranged from 40 to 54 points across cohorts. For a 10-point increase in HDI score (representing adherence to an additional WHO guideline), the pooled adjusted hazard ratios were 0.90 (95% confidence interval (CI): 0.87, 0.93) for men and women combined, 0.89 (95% CI: 0.85, 0.92) for men, and 0.90 (95% CI: 0.85, 0.95) for women. These estimates translate to an increased life expectancy of 2 years at the age of 60 years. Greater adherence to the WHO guidelines is associated with greater longevity in elderly men and women in Europe and the United States.

Keywords: Consortium on Health and Ageing: Network of Cohorts in Europe and the United States; aging; cohort; diet; longevity; meta-analysis.

© The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Cohort-specific and pooled hazard ratios (HRs) of all-cause mortality in relation to a 10-point increase in Healthy Diet Indicator (HDI) score, adjusted for sex, educational level, smoking status, energy intake, alcohol consumption, and physical activity level in the Consortium on Health and Ageing: Network of Cohorts in Europe and the United States (CHANCES), 1988–2011. Bars, 95% confidence intervals (CIs). Cohorts are ordered according to year of baseline assessment, beginning with the oldest. I2 value is expressed as the percentage of total variability caused by heterogeneity. All data were obtained from CHANCES (www.chancesfp7.eu). EPIC-Elderly, European Prospective Investigation Into Cancer and Nutrition–Elderly Study; HAPIEE, Health, Alcohol, and Psychosocial Factors in Eastern European Countries Study; NIH-AARP, National Institutes of Health–AARP Diet and Health Study; SENECA, Survey in Europe on Nutrition and the Elderly, a Concerted Action.

Figure 2.

Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) in the Consortium on Health and Ageing: Network of Cohorts in Europe and the United States (CHANCES), 1988–2011, for the association between a 10-point increase in Healthy Diet Indicator (HDI) score and all-cause mortality A) stratified for potential effect modifiers; B) stratified for cohort-specific characteristics; and C) after several exclusion criteria have been applied. Body mass index (BMI) is weight (kg)/height (m)2. I2 values are expressed as percentages of total variability caused by heterogeneity. CZ, Czech Republic; DK, Denmark; EPIC-E, European Prospective Investigation into Cancer and Nutrition–Elderly Study; GR, Greece; HAPIEE, Health, Alcohol, and Psychosocial Factors in Eastern European Countries Study; NA, not applicable; NIH-AARP, National Institutes of Health–AARP Diet and Health Study; NL, Netherlands; PL, Poland; RES, Rotterdam Elderly Study; RU, Russia; SENECA, Survey in Europe on Nutrition and the Elderly, a Concerted Action; SP, Spain; SW, Sweden.

Figure 2.

Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) in the Consortium on Health and Ageing: Network of Cohorts in Europe and the United States (CHANCES), 1988–2011, for the association between a 10-point increase in Healthy Diet Indicator (HDI) score and all-cause mortality A) stratified for potential effect modifiers; B) stratified for cohort-specific characteristics; and C) after several exclusion criteria have been applied. Body mass index (BMI) is weight (kg)/height (m)2. I2 values are expressed as percentages of total variability caused by heterogeneity. CZ, Czech Republic; DK, Denmark; EPIC-E, European Prospective Investigation into Cancer and Nutrition–Elderly Study; GR, Greece; HAPIEE, Health, Alcohol, and Psychosocial Factors in Eastern European Countries Study; NA, not applicable; NIH-AARP, National Institutes of Health–AARP Diet and Health Study; NL, Netherlands; PL, Poland; RES, Rotterdam Elderly Study; RU, Russia; SENECA, Survey in Europe on Nutrition and the Elderly, a Concerted Action; SP, Spain; SW, Sweden.