Sustainable dietary patterns and all-cause mortality among US adults

Sustainable dietary patterns that incorporate multiple dimensions may have benefits for both human health and the environment. We examined the association between sustainable dietary patterns assessed by using the Sustainable Diet Index-US (SDI-US) and mortality in US adults.

This study used data from the National Health and Nutrition Examination Survey 2007-18 (N = 22 414 aged ≥20 years). The SDI-US (range: 4-20) was composed of four sub-indices representing nutritional, environmental, economic and sociocultural dimensions, and was computed using 24-h dietary recalls, food expenditures and food preparation habits. A higher score indicates a more sustainable dietary pattern. All-cause mortality from baseline until 31 December 2019 was obtained through linkage to the National Death Index. Hazard ratios (HRs) with 95% CIs were estimated using Cox proportional-hazards models, adjusting for covariates.

During 150 386 person-years of follow-up, 2100 total deaths occurred and the median SDI-US was 9.8 in Quintile 1 (Q1) and 16.3 in Quintile 5 (Q5). In a multivariable-adjusted model, the highest SDI-US quintile was associated with a 36% reduction in mortality risk (Q5 vs Q1, HR 0.64, 95% CI 0.49-0.84, P = 0.002) compared with the lowest quintile. When stratified by age (P interaction = 0.002), an inverse association between SDI-US and mortality was observed in younger adults (<65 years, HR 0.41, 95% CI 0.25-0.68, P = 0.001) but not in older adults (≥65 years, HR 0.91, 95% CI 0.71-1.16, P = 0.15).

A higher SDI-US score was associated with lower mortality risk among US adults, particularly in younger adults.