Investigating Causal Associations of Diet Compositions with the Risk of Lung Cancer.

Objective: This study aimed to investigate the causal relationship between diet compositions and lung cancer (LC) risk.

Methods: A two-sample Mendelian randomization (MR) analysis was performed to assess the causal relationship between diet and LC risk, including three LC subtypes. Instrumental variables (IVs) for three diet compositions were selected from genome-wide association studies (GWAS). Summary statistics for LC and its subtypes came from the largest meta-analysis. The inverse-variance weighted (IVW) method was used as the main MR analysis, with sensitivity analyses to ensure result robustness. Then, we conducted an observational study using data from National Health and Nutrition Examination Survey (NHANES) to verify the relationship.

Results: Our results showed significant evidence that fat intake was correlated with the lower risk of lung adenocarcinoma. There were also suggestive correlations between fat intake and overall LC. However, no significant associations were found between other macronutrients and LC risk. NHANES data further showed that higher polyunsaturated fatty acid (PUFA) intake was linked to better outcomes in LC patients.

Conclusion: PUFA intake may have a protective effect against LC. Adjusting dietary proportions could potentially help in the primary prevention of LC.