Those who regularly use fish oil supplementation have a lower risk of incident chronic obstructive pulmonary disease (COPD), regardless of their genetic predisposition for the disease, according to study findings published recently in Clinical Nutrition.
Researchers sought to evaluate the association between habitual fish oil supplementation and incident COPD risk and to examine a possible effect modification from genetic predisposition.
The investigators conducted a prospective cohort study of adult participants from the UK Biobank who completed a questionnaire on habitual fish oil supplement usage between 2006 and 2010. Participants with prevalent COPD, chronic bronchitis, or emphysema and those with incomplete data regarding fish oil usage were excluded from the study. A total of 484,414 participants (40-69 years of age; 54.6% women) were followed through 2018; of these, 457,154 had genetic data. Habitual fish oil supplementation was reported by 31.4% of participants at baseline; these participants were more likely to be female, older, nonsmoking, physically active, and to take vitamin supplements, minerals, and NSAIDs.
The researchers developed a weighted genetic risk score (GRS) for COPD using more than 100 single nucleotide polymorphisms and stratified study participants into high, intermediate, and low genetic risk categories. Cox regression models estimated hazard ratios (HRs), with adjustments for health conditions, lifestyle behaviors, sociodemographics, and additional potential confounders.
During the follow-up period, there were 8860 incident COPD events; of those, 6232 occurred in participants who did not use fish oil supplementation. In age- and sex-adjusted analyses, the researcher found a significant inverse association
between fish oil use and the risk of COPD (HR 0.74; 95% CI, 0.71-0.77). The multivariable-adjusted model showed that fish oil supplementation was significantly associated with lower risk of incident COPD (adjusted HR 0.88; 95% CI, 0.84-0.93). Subgroup and sensitivity analysis according to potential risk factors supported these findings.
Researchers noted that while a higher GRS was significantly associated with a higher risk of incident COPD, they found no significant interaction between fish oil use and
GRS strata in this association with COPD (P [for interaction] =.88).
Study limitations include no record of dose, formulation, or duration of fish oil use; the misrepresentation in Biobank data of participants with COPD diagnosed by their general practitioner and never treated in hospital; inconsistent follow-up times; residual confounding due to unavailable Biobank data, lack of generalizability from the UK Biobank to the general population; and the possibility of reverse causality.
“Our findings suggest that habitual fish oil supplementation is associated with a lower risk of incident COPD, irrespective of genetic predisposition,” researchers concluded.
Li ZH, Song WQ, Shen D, et al. Habitual fish oil supplementation and incident chronic obstructive pulmonary disease: data from a prospective cohort study. Clin Nutr. Published online October 8, 2022. doi:10.1016/j.clnu.2022.10.002