Association between n-3 PUFA and lung function: results from the NHANES 2007-2012 and Mendelian randomisation study

This study aimed to investigate the association between n-3 PUFA and lung function. First, a cross-sectional study was conducted based on the National Health and Nutrition Examination Survey (NHANES) 2007-2012 data. n-3 PUFA intake was obtained from 24-h dietary recalls. A multivariable linear regression model was used to assess the observational associations of n-3 PUFA intake with lung function. Subsequently, a two-sample Mendelian randomisation (MR) was performed to estimate the potential causal effect of n-3 PUFA on lung function. Genetic instrumental variables were extracted from published genome-wide association studies. Summary statistics about n-3 PUFA was from UK Biobank. Inverse variance weighted was the primary analysis approach. The observational study did not demonstrate a significant association between n-3 PUFA intake and most lung function measures; however, a notable exception was observed with significant findings in the highest quartile for forced vital capacity (FVC) and % predicted FVC. The MR results also showed no causal effect of circulating n-3 PUFA concentration on lung function (forced expiratory volume in one second (FEV1), beta = 0<middle dot>01301, SE = 0<middle dot>01932, P = 0<middle dot>5006; FVC, beta = -0<middle dot>001894, SE = 0<middle dot>01704, P = 0<middle dot>9115; FEV1:FVC, beta = 0<middle dot>03118, SE = 0<middle dot>01743, P = 0<middle dot>07359). These findings indicate the need for further investigation into the impact of higher n-3 PUFA consumption on lung health.