Association between dietary intake of omega-3 polyunsaturated fatty acids and all-cause and cardiovascular mortality among hypertensive adults: Results from NHANES 1999-2018

Abstract

Background: Hypertensive adults are at a higher risk of cardiovascular morbidity and mortality. Dietary omega-3 polyunsaturated fatty acids (N3-PUFA) intake has been associated with cardiovascular benefits. However, few studies have specifically investigated whether dietary intake of N3-PUFA is associated with lower risk of all-cause and cardiovascular mortality among hypertensive adults in the U.S.

Methods: This prospective cohort study included 26,914 hypertensive individuals 18 years or older who participated in 10 NHANES cycles from 1999 to 2018. Dietary levels of N3-PUFA were obtained from the 24-hour dietary recalls. The dietary data were linked to mortality records from the National Death Index through December 31, 2019. The associations between dietary N3-PUFA levels and mortality were evaluated by constructing the Multivariable Cox Proportional Hazards models.

Results: We observed an increasing trend of dietary N3-PUFA intake levels over the years, mainly driven by alpha-linolenic acid (ALA). Lower all-cause mortality risk was observed among hypertensive adults with higher consumption of total N3-PUFA [adjusted hazards ratio, 95% confidence interval: 0.91 (0.86, 0.97)], plant-based ALA [0.88 (0.83, 0.93)], fish oil-based eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) [0.91 (0.83, 0.99)], EPA [0.93 (0.88, 0.98)], docosapentaenoic acid (DPA) [0.73 (0.58, 0.91)], or DHA [0.95 (0.90, 0.99)]. Hypertensive adults were at lower risk of cardiovascular mortality if their diet contained higher levels of total N3-PUFA [0.68 (0.53, 0.88)], ALA [0.89 (0.80, 0.99)], EPA [0.87 (0.79, 0.97)] or DPA [0.86 (0.78, 0.95)]. Weighted quantile sum analysis showed that ALA, EPA, and DPA were the main contributors of the N3-PUFA benefits against mortality among hypertensive adults.

Conclusions: Dietary intake of N3-PUFA, particularly ALA, EPA, and DPA, was associated with lower risk of all-cause and cardiovascular mortality among U.S. hypertensive adults. These findings suggest that increasing dietary intake of N3-PUFA may serve as a potential strategy to lower hypertension-associated mortality risk.

Keywords: Alpha-linolenic acid; Docosapentaenoic acid; Eicosapentaenoic acid; Hypertension; Mortality; Omega-3 polyunsaturated fatty acid.