Inflammation plays a role in the decline of lung function and the development of chronic obstructive pulmonary disease, a lung condition that affects roughly 300 million people worldwide. However, omega-3s exert robust anti-inflammatory effects. A new study suggests that omega-3 fatty acids might slow the decline of lung function.

Researchers conducted a two-part study. First, they reviewed data from the National Heart, Lung, and Blood Institute Pooled Cohorts Study, which measured plasma omega-3 concentrations in more than 15,000 participants. The study also assessed the participants' lung function, measured via forced expiratory volume-1 (FEV1) and forced vital capacity (FVC). FEV1 measures the volume of air one can exhale in one second; FVC measures the volume of air one can exhale forcefully in one breath.

They found that higher concentrations of omega-3s, especially docosahexaenoic acid (DHA), a marine-derived omega-3 fatty acid, delayed lung function decline. Increasing DHA by just 1 percent of total fatty acids slowed forced expiratory volume losses by 1.4 milliliters (mL) per year and forced vital capacity by 2.0 mL per year. To provide context for these effect sizes, note that compared to non-smokers, current and former smokers experience approximately an 8.0 mL per year and 2.0 mL per year more rapid decline in lung function, respectively.

In the second part of the study, they analyzed genetic data of more than 500,000 participants enrolled in the UK Biobank study to determine how genetic markers that predict dietary omega-3 fatty acid levels correlate with lung health. They found that higher omega-3 concentrations were associated with better lung function.

These findings suggest that higher blood concentrations of omega-3 fatty acids, especially DHA, can benefit lung health. Learn more about omega-3s in our comprehensive overview article.

• Read study abstract.