Mediterranean Diet, Fat Intake, and Lung Cancer Outcomes

Key Takeaways

• Greater Mediterranean diet adherence was associated with lower lung cancer incidence and lower lung cancer-specific mortality after adjustment.
• Higher polyunsaturated fat intake was associated with lower incidence and mortality, whereas higher saturated fat intake was associated with higher risk.
• Replacing 1% of saturated fat energy with polyunsaturated fat was associated with 9% lower incidence and 10% lower mortality, and high AMED plus polyunsaturated fat intake was associated with better survival.

Among 191,139 cancer-free UK Biobank participants, higher Mediterranean diet adherence was associated with lower lung cancer risk, with an HR of 0.66 (95% CI 0.58-0.77) for the highest versus lowest quartile.

The study measured diet before lung cancer outcomes and assessed total dietary fat and fat subtypes alongside diet quality. Lung cancer-specific mortality followed a similar pattern, and survival after diagnosis was evaluated among participants who later developed lung cancer.

Dietary intake was measured with the validated Oxford WebQ 24-hour dietary questionnaire. Mediterranean diet adherence was summarized with the Alternate Mediterranean diet score, while total fat and fat subtype intakes were expressed as proportions of total energy intake.

Higher Mediterranean diet adherence was associated with lower lung cancer-specific mortality after adjustment, with an HR of 0.61 (95% CI 0.50-0.74) for the highest versus lowest quartile. Higher polyunsaturated fat intake showed a similar pattern, with lower lung cancer risk and lower lung cancer-specific mortality, at HRs of 0.82 (95% CI 0.71-0.95) and 0.77 (95% CI 0.63-0.94). In contrast, higher saturated fat intake was associated with higher incidence, with an HR of 1.25 (95% CI 1.09-1.45), and with higher lung cancer-specific mortality, with an HR of 1.23 (95% CI 1.01-1.49).

In isocaloric substitution analyses, replacing 1% of energy from saturated fat with polyunsaturated fat was associated with a 9% lower lung cancer incidence risk and a 10% lower lung cancer mortality risk. Survival after diagnosis was also evaluated among participants who later developed lung cancer. In that group, high pre-diagnosis Alternate Mediterranean diet scores plus high polyunsaturated fat intake were associated with better post-diagnosis survival than low-score, low-intake patterns, with an HR of 0.77 (95% CI 0.61-0.96).