BOSTON, MASSACHUSETTS. The idea that fish and fish oils may protect against lung disease developed from early studies of the dietary habits of Greenland Eskimos. Dr. D.F. Horrobin hypothesized that the high content of omega-3 fatty acids in the Eskimo diet is at least partially responsible for the low prevalence of lung disease in this population group. This makes biological sense inasmuch as omega-3 fatty acids (notably from fish and fish oils) are known to inhibit the synthesis of the inflammatory eicosanoids involved in lung diseases.
Dr. Joel Schwartz, MD of the Harvard Medical School has just published a review of the evidence concerning omega-3 fatty acids and lung disease. Dr. Schwartz concludes that there is good evidence that a high intake of fish helps retard the age-related decline in lung capacity observed among both smokers and non-smokers. He also points out that one long term trial of fish oil supplementation in adult asthma patients showed significant benefits, but that shorter trials (less than 1 year) have not confirmed these findings. Two Australian studies have shown that consumption of fresh fish (particularly oily fish) protects children against wheezing and asthma. The evidence concerning fish oil and cystic fibrosis is controversial. Some studies have shown that fish oil supplementation suppresses the formation of the inflammatory eicosanoids which are characteristic of cystic fibrosis; however, little or no clinical improvements are noted in these studies. Other studies have found a significant protective effect of fish and fish oil in regard to emphysema (chronic obstructive pulmonary disease) and chronic bronchitis especially among smokers.
Dr. Schwartz concludes that there is a good case for fish and fish oils being protective against the development of chronic lung diseases, but that more research is needed to establish conclusive proof of benefits.
Schwartz, Joel. Role of polyunsaturated fatty acids in lung disease. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 393S-96S