Dietary quality and survival among middle-aged and older adults in the NHANES I epidemiologic follow-up study

The association of dietary quality and survival was examined among 6249 adults aged 45–74 years in the First National Health and Nutrition Examination Survey (1971–74) who were traced at the 1987 NHANES I Epidemiologic Followup Survey. The baseline 24-hour recall diet was defined as poor quality if 5 or more nutrients (of the 8 examined) were below 67% of the Recommended Dietary Allowance. Across six age/sex groups, relative hazards of death for persons with poor dietary quality ranged from 1.2 to 1.9 when adjusted for age alone. When adjusted for socioeconomic and health measures, the dietary quality-survival associations were weakened considerably. We conclude that non-dietary factors explain much of the apparent association, and that the importance of these factors varies across age and sex categories. Inclusion of measures of employment status, smoking, and chronic conditions, as well as the more traditional socioeconomic confounders, is important for the proper interpretation of diet-survival relationships.