Asthma is a respiratory condition characterized by narrowed airways and difficulty breathing. It commonly manifests in early childhood and affects more than 339 million people worldwide. Findings from a new study suggest that dietary intake of omega-3 fatty acids among children who carry a common variant in the fatty acid desaturase gene reduces the risk of developing asthma.

Fatty acid desaturase is an enzyme that drives the biosynthesis of mono- and polyunsaturated fatty acids in the body. Impairments in the expression and activity of fatty acid desaturases drives many pathological conditions.

The authors of the study analyzed data from healthy male and female children enrolled in the Avon Longitudinal Study of Parents and Children, a prospective birth cohort study conducted in England. They assessed dietary intake of omega-3 fatty acids from fish via food frequency questionnaires when the children were 7 years old and collected information about the incidence of asthma among the children when they were 11 and 14 years of age. They replicated their analysis in the Swedish BAMSE birth cohort.

The authors of the study found no links between intake of omega-3 fatty acids from fish and the incidence of asthma in the full group of children. But when they looked at the subset of children who carried a variant in the fatty acid desaturase gene, they found that high intake of omega-3 fatty acids from fish reduced the risk of developing asthma 51 percent. These findings were replicated in the BAMSE cohort.

These findings suggest that dietary intake of fish rich in omega-3 fatty acids during childhood reduces the risk of developing asthma among children who carry a genetic variant of an enzyme involved in fatty acid synthesis. The authors of the study cautioned that their study was observational and did not identify any causes to explain the relationship.

• Link to study abstract.