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

This study aimed to investigate the association between consumption of ultra-processed foods (UPFs) and leucocyte telomere length (LTL). 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. 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. 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.