The Importance of EFA Supplementation in Cystic Fibrosis

Docosahexaenoic acid, or DHA (not to be confused with DHEA!), is an essential fatty acid. The work of Steven D. Freedman, Juan G. Alvarez, and their colleagues at the Harvard Medical School, has recently shown that cftr-knockout mice have a 3-fold decrease in membrane-bound DHA and a 3-fold increase in membrane-bound arachidonic acid (AA), another essential fatty acid. Arachidonic acid and DHA compete with each other through esterification for placement as membrane phospholipids. AA tends to stimulate both inflammation and mucus secretion. The researchers are unclear how this lipid imbalance is linked to the genetic mutation causing CF. However, the lipid imbalance was most pronounced in the ileum, pancreas, and lungs of the cftr knockout mice, with the heart also being affected. The brain and kidneys of the mice seemed not to be severely affected by this lipid imbalance. This is preliminary evidence that CF pathology is related to the degree of imbalance between AA and DHA. The organs with the greatest imbalances are also the organs most affected by CF. The researchers are able to rule out intestinal malabsorption or hepatic dysfunction as the cause of the imbalance, and so somehow, then, the lipid imbalance must be related to faulty CFTR function.

What was most heartening was that there is some hope that this lipid imbalance could be reversed and normalized by oral administration of DHA. (Though fish oil is high in DHA, it also contains EPA which competes with DHA. The researchers thus used pure DHA.) Oral admnistration of DHA reversed pancreatic and ileal pathology in these mice. (Luminal diameter and villus height were normalized.) In addition, exaggerated neutrophil infiltration into the CF lung in response to Pseudomonas LPS was normalized. If these results could be duplicated in humans, this would be a tremendous therapeutic breakthrough, as DHA would represent one of the few therapies that would act to help prevent the deterioration of a CF person's body.

Though other omega-3 fatty acids, such as alpha-linoleic acid or EPA, can lower membrane-bound AA (an omega-6), neither normalizes DHA levels in CF and thus cannot reverse pathology. Only DHA both lowered AA and increased DHA levels in CF, which resulted in the normalization noted above.

We believe CF persons should give strong consideration to adding DHA capsules to their daily regimen.