Association Between Ultra-Processed Food Consumption and Leucocyte Telomere Length: A cross-sectional study of UK Bioban

Objective: This study aimed to investigate the association between consumption of ultra-processed foods (UPFs) and leucocyte telomere length (LTL). Methods: This cross-sectional study utilized data from the UK Biobank, including a total of 64,690 participants. LTL was measured using Q-PCR with natural logarithmic conversion and Z-score normalization. Dietary data were collected through a 24-hour recall questionnaire from 2009 to 2010. UPFs were identified using the Nova food classification and analyzed as either a continuous or categorical variable respectively. Multiple linear regression models were employed to analyze the association between UPF consumption and LTL. Results: The included participants had an average age of 56.26 years, of whom 55.2% were female. After adjusting for sociodemographic, lifestyle-related and anthropometric variables, LTL exhibited a decrease of 0.005 (95% CI: -0.007, -0.002) with one UPF serving/day increase. Compared to participants consuming ≤ 3.5 servings/day, those consuming 3.5 to < 6, 6 to ≤ 8 and > 8 servings/day showed a shortening of LTL by 0.025 (95% CI: -0.047, -0.004), 0.034 (95% CI: -0.055, -0.012) and 0.038 (95% CI: -0.062, -0.015), respectively (P for trend = 0.001). Subgroup analyses by UPF subclasses revealed that consumption of ready-to-eat/heated food (β = -0.008, 95% CI: -0.014, -0.002), beans and potatoes (β = -0.024, 95% CI: -0.039, -0.009), animal-based products (β = -0.011, 95% CI: -0.019, -0.004), artificial sugar (β = -0.014, 95% CI: -0.025, -0.004), and beverages (β = -0.005, 95% CI: -0.009, -0.001) showed negative associations with LTL. Conversely, breakfast cereals (β = 0.020, 95% CI: 0.004, 0.036) and vegetarian alternatives (β = 0.057, 95% CI: 0.027, 0.086) showed positive correlations with LTL. Conclusions: Our study found that a higher consumption of total UPFs was associated with a shorter LTL. However, some subclass UPFs may be associated with longer LTL, depending on their nutritional composition.