The association between polyunsaturated fatty acids and chronic obstructive pulmonary disease: a meta-analysis

Background: Chronic obstructive pulmonary disease (COPD) is a common respiratory disease, and its development and prognosis are influenced by many nutrients. However, the relationship between polyunsaturated fatty acids (PUFAs) and COPD remains unclear. Methods: This study searched all literature reports on PUFAs and COPD based on electronic databases from their inception up to October 2023. Meta-analysis was conducted to evaluate the differences in PUFAs between COPD patients and controls, the risk of COPD in subjects with different levels of PUFA concentrations, and the effect of PUFA supplementation on COPD. Results: A total of nineteen studies met our inclusion criteria, which included 155 636 subjects. Our meta-analysis results showed that the daily dietary intake of PUFAs was lower in COPD patients than in controls (SMD = -0.80 g, 95% CI: -1.28, -0.31 g, I² = 98.6%, P < 0.001). Meanwhile, the lower n-3 PUFA levels and higher n-6 PUFA levels were associated with an increased risk of COPD (effect size n-3 = 0.87, 95% CI: 0.77, 0.98, I² = 52.2%, P = 0.018; effect size n-6 = 1.23, 95% CI: 1.05, 1.43, I² = 75.2%, P < 0.001). Furthermore, the content of low-density lipoprotein cholesterol in the PUFA supplementation group was higher than that in the control group (SMD = 0.63 mg dL^-1, 95% CI: 0.15, 1.12 mg dL^-1, I² = 0.0%, P = 0.697). Conclusions: Our meta-analysis indicated a potential relationship between PUFAs and COPD. More large-scale prospective cohort studies and clinical trials are necessary to validate this relationship.