Nutrition/Obesity
Ultra-processed foods, dietary inflammation, and diet quality in relation to mortality risk in U.S. adults Penias Tembo* Penias Tembo Tembo Tembo Tembo University of South Carolina
Background: Prior studies have examined ultra-processed foods (UPF), dietary inflammatory potential, and diet quality separately, limiting inference on their independent and joint associations with mortality. We aimed to evaluate the independent and joint associations of UPF, inflammatory diet, and diet quality with mortality risk among U.S. adults.
Methods: This longitudinal study analyzed data from the National Health and Nutrition Examination Survey (NHANES) cycles from 2005–2018, including a representative sample of 25,506 U.S. adults. Exposures of interest were UPF intake and Dietary Inflammatory Index (DII) and Healthy Eating Index (HEI) scores. The primary outcome was mortality. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by survey-weighted Cox proportional hazards regression models.
Results With a median 7.6 years of follow-up, we documented 2577 deaths. Higher UPF and DII scores were associated with increased all-cause mortality (HR Quintile 5 vs. 1 [95% CI]: UPF, 1.30 [1.07–1.59]; DII, 1.55 [1.28–1.88]), and HEI was inversely related to mortality (0.75 [0.62–0.91]). When modelled jointly, DII (1.48 [1.20–1.82]) and HEI (0.79 [ 0.65–0.97]) remained independently associated with mortality, whereas UPF was attenuated (1.15 [0.93–1.41]). Significant interactions were observed between UPF and both DII (P = 0.02) and HEI (P = 0.01); higher mortality risk was evident only among individuals with high DII or low HEI. Joint analyses showed the highest risk among participants with high UPF, high DII, and low HEI (1.34 [1.14–1.58]). Among UPF subcategories, beverages (HR Tertile 3 vs. 1 [95% CI]: 1.16 [1.01–1.34]) and ready-to-eat/heat meals (1.14 [1.00–1.31]) were positively associated with mortality, whereas sauces/cheese spreads showed an inverse association (0.81 [0.70–0.94]).
Conclusions UPF intake was associated with higher mortality risk, particularly among individuals with poor diet quality or high dietary inflammation.
