Association between adherence to healthy dietary patterns and life expectancy in US adults: A prospective cohort study

The relationship between adherence to various healthy dietary patterns and life expectancy among US adults remained unclear. This study analyzed a representative sample of individuals aged 18 and older, selected from the National Health and Nutrition Examination Surveys. Six common dietary patterns, including the Alternate Mediterranean Diet (AMED), Healthy Eating Index 2015 (HEI-2015), Alternate Healthy Eating Index (AHEI), Dietary Approaches to Stop Hypertension (DASH), Dietary Inflammatory Index (DII), and Healthful Plant-based Diet Index (HPDI), were assessed. Life table method was used to evaluate the association between adherence to six dietary patterns and life expectancy, with groups stratified by sex, race and ethnicity. For the highest adherence to each dietary pattern, the estimated life expectancy at age 50 was 33.22 years (95% CI: 32.65, 33.82) for the AMED, 32.12 years (31.66, 32.61) for HEI-2015, 33.63 years (32.61, 34.69) for DII, 31.82 years (31.24, 32.4) for HPDI, 31.91 years (31.38, 32.43) for AHEI, and 32.66 years (32.11, 33.19) for DASH. Compared to the lowest adherence, the highest adherence increased life expectancy by 4.02 years (3.03, 5) for AMED, 2.57 years (1.62, 3.58) for HEI-2015, 4.27 years (2.72, 5.87) for DII, 1.18 years (0.26, 2.07) for HPDI, 1.92 years (1.04, 2.77) for AHEI, and 3.1 years (2.07, 4.04) for DASH. These gains varied significantly by sex, race or ethnicity. Adhering to each of the six healthy dietary patterns contributes to increased life expectancy among US adults, with greater adherence consistently associated with a larger increase. Our findings suggest that these healthy dietary patterns could be part of a healthy lifestyle, supporting the recommendations in the Dietary Guidelines for Americans to encourage individuals to adopt various healthy dietary patterns.