Omega-3 fatty acids in foods and supplements may keep your lungs healthy

Omega-3 fatty acids, which are abundant in foods like fish and are also a popular dietary supplement, show promise in maintaining lung health, according to a new study. Researchers gathered evidence from a large, multi-faceted research project among healthy adults supported by the National Institutes of Health. This work provides the most compelling evidence yet of this association and highlights the importance of including omega-3 fatty acids in one’s diet – especially since many Americans fail to meet current nutritional guidelines.

“We know a lot about the role of diet in cancer and cardiovascular diseases, but the role of diet in chronic lung disease is somewhat understudied,” says corresponding author Patricia A. Cassano, Ph.D., director of the Division of Nutritional Sciences at Cornell University, in a media release. “This study adds to growing evidence that omega-3 fatty acids, which are part of a healthy diet, may be important for lung health too.”

In recent years, there has been an increased interest in gaining a clearer understanding of whether nutritional interventions may contribute to or influence lung disease prevention. Prior projects have suggested that omega-3 fatty acids may help, probably due to their established anti-inflammatory actions. However, robust studies of this association have been lacking – until now.

The research team put together a two-part study investigating the link between omega-3 fatty acid levels in the blood and lung function over time. The first part entailed researchers conducting a longitudinal, observational study involving 15,063 Americans from the NHLBI Pooled Cohorts Study – which is a large collection of NIH-funded studies intended to help researchers study determinants of personalized risk for chronic lung disease.

Study participants were all generally healthy when the study began, and the majority showed no evidence of chronic lung disease. The cohort was made up of a racially diverse group of adults, with an average age of 56, with 55 percent being female. Participants were tracked for an average of seven years, and in some cases, for as long as 20 years.

This longitudinal study showed that higher levels of omega-3 fatty acids in a person’s blood had an association with a lower rate of lung function decline. Study authors saw the strongest associations for docosahexaenoic acid (DHA), an omega-3 fatty acid that is found in high levels among fatty fish like salmon, tuna, and sardines. DHA is also available as a dietary supplement.

The second part of the project entailed researchers analyzing genetic data from a large study of European patients (over 500,000 participants) from the UK Biobank. Certain genetic blood markers were studied as an indirect measure, or proxy, for dietary omega-3 fatty acid levels. This was done to gauge how they correlated with lung health. The ensuing results displayed that higher levels of omega-3 fatty acids, including DHA, were associated with better lung function.

A caveat of the current study worth mentioning is that it only included healthy adults. Researchers are now collaborating with the COPDGene study to examine blood levels of omega-3 fatty acids in relation to the rate of decline in lung function among people with chronic obstructive pulmonary disease or COPD, including heavy smokers, in order to ascertain if the same beneficial associations are found.

“We’re starting to turn a corner in nutritional research and really moving toward precision nutrition for treating lung diseases,” adds study first author Bonnie K. Patchen, Ph.D., a nutritionist and member of Cassano’s research team at Cornell. “In the future, this could translate into individualized dietary recommendations for people at high risk for chronic lung disease.”

For now, study authors point out that the U.S. Department of Agriculture’s Dietary Guidelines for Americans recommends eating at least two servings of fish per week – a feat most Americans fail to accomplish. Besides fish and fish oil, other sources of omega-3 fatty acids include nuts and seeds, plant oils, and fortified foods.

“This large population-based study suggests that nutrients with anti-inflammatory properties may help to maintain lung health,” concludes James P. Kiley, Ph.D., director of the NHLBI’s Division of Lung Diseases. “More research is needed, since these findings raise interesting questions for future prospective studies about the link between omega-3 fatty acids and lung function.”

The study is published in the American Journal of Respiratory and Critical Care Medicine.