I am commonly asked about the relationship between diet and asthma. Patients are very interested to know if there are foods that are worsening their asthma or if certain foods might improve their asthma.

One of the common foods thought to potentially improve or prevent asthma is fish because of the high content of omega-3 fatty acids in some types of fish. Certain populations (e.g. Eskimo) with high omega-3 intakes have been noted to have comparably low rates of asthma. The theory is that high levels of omega-3 fatty acids have anti-inflammatory properties that improve or prevent asthma.

However, studies giving omega-3 fatty acid supplementation to patients have not generally shown improvements in asthma function or deceases in symptoms or medication use. While there was no significant asthma benefit, there were also no side effects.

So why do populations eating a lot of fish have less asthma, but giving fish oil showed no benefit? Possibly it is not the omega-3 fatty acids, but some other yet undetermined substance, that is improving asthma. Possibly it has more to do with a general good diet as opposed to a particular vitamin or mineral. While increasing your fish consumption may not improve your asthma, fish can be a good part of a healthful diet.

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