Mediterranean diet adherence, healthy sleep, and lung cancer risk: a prospective study of 192,034 UK Biobank participants

PURPOSE: Diet and sleep have each been associated with cancer risk, but their joint association with lung cancer risk remains unclear. We investigated the association between a joint Mediterranean diet-sleep pattern and lung cancer risk in the UK Biobank. We also evaluated whether siesta modified the association between Mediterranean diet adherence and lung cancer risk. METHODS: Participants were drawn from the UK Biobank. Mediterranean diet adherence was assessed using an adapted Mediterranean Diet Adherence Screener, and sleep was evaluated using a composite score based on five sleep behaviors. Mediterranean diet and sleep scores were categorized into tertiles and jointly classified into nine levels of a diet-sleep pattern. Associations were examined using Fine-Gray proportional subdistribution hazards models that accounted for competing risks from all-cause mortality, yielding subdistribution hazard ratios (SHRs) and 95% confidence intervals (CIs). RESULTS: A total of 192,034 participants (median age 57 years; 54% were female) were included and followed for a median of 14 years, during which 1156 incident lung cancer cases occurred. Compared with participants in the lowest level, those in the highest level had a 43% lower risk of lung cancer (SHR 0.57, 95% CI 0.41-0.79; P = 0.001). No evidence was found that siesta modified the association between Mediterranean diet adherence and lung cancer risk. CONCLUSIONS: The joint Mediterranean diet-sleep pattern was associated with a lower risk of lung cancer, although this finding should be interpreted as an observational association rather than evidence of causality.