Anti-inflammatory diets might mitigate the association between sedentary behaviors and the risk of all-cause deaths.

Background and aims: The pathogenic mechanism of sedentary behavior involves chronic inflammation, which can be affected by dietary inflammation. This study aimed to determine the association between dietary inflammation, sedentary behavior, and risk of death.

Methods: Data from the National Health and Nutrition Examination Survey (2007-2018) were analyzed. Sedentary behavior was evaluated using self-reported sitting hours in a day, and dietary inflammation was assessed using dietary inflammatory index (DII). Deaths were ascertained through the National Death Index until December 31, 2019. The interaction between dietary inflammation and sedentary behavior was evaluated through multivariable Cox regression analysis.

Results: 18,425 participants (mean age: 48.2 years; female proportion, 51.7%) were involved for analysis. During a median follow-up of 7.7 years, we confirmed 1,960 all-cause and 488 cardiovascular deaths. After adjustment for confounders, both pro-inflammatory diets and sitting for 6 h/d or more were risk factors for all-cause and cardiovascular deaths (P < 0.05). Of note, we found that dietary inflammation modified the association between sitting time and the risk of all-cause deaths (P for interaction = 0.03). Compared with shorter sitting time (< 6 h/d), prolonged sitting time (≥ 6 h/d) was correlated with an elevated risk of all-cause deaths among participants with pro-inflammatory diets (DII ≥ 0) (HR: 1.50, 95%CI: 1.35-1.66, P < 0.001), but not among participants with anti-inflammatory diets (DII < 0) (HR: 1.20, 95%CI: 0.98-1.46, P = 0.08).

Conclusions: Dietary inflammation modified the association between sedentary behavior and the risk of all-cause deaths. Anti-inflammatory diets might mitigate the detrimental effects of sedentary behavior on survival in US adults.