Does DHA omega-3 interfere with Cyclosporine? Will it help with retinitis pigmentosa?
A number of controlled clinical trials have evaluated the potential effects of supplementation with DHA+EPA in the form of encapsulated fish oil in kidney transplant recipients maintained on cyclosporine as the immunosuppressive regimen. Overall, these studies have not provided sufficient evidence for recommending fish oil therapy contained DHA/EPA to improve patient outcomes. In some of these studies, fishy after-taste and minor gastrointestinal disturbances were found although these did not result significant patient drop-outs. No clinically-based evidence has come forth with respect to DHA omega-3 having an interfering effect with cyclosporine. It is noteworthy that DHA is consumed at levels of several hundred mg per day in Japan based on their high intake of fish/seafood in contrast to the much lower intakes (approximately 80 mg DHA/day) in North America.
Retinitis pigmentosa is a degenerative condition of the retina with a world wide occurrence of approximately 1 in 3000-4000 people. A randomized placebo-controlled clinical trial employing DHA supplementation for X-linked retinitis pigmentosis (RP) has been performed using daily intakes of 400mg of DHA per day over a four-year duration. Clinical measures in this trial included the electroretinogram (ERG) which records electrical events in the retina as associated with stimulation from brief flashes of light. This trial, while showing considerable elevations in blood levels of DHA as expected, did not show significant benefits with respect to visual outcomes that would fulfill the criteria for changing current clinical practice. However, Dr. David Birch (Retina, 25: S52-S54 (2005)) suggested that there appeared to be an indication that the increased levels of DHA in the circulation were associated with some reduction in the rate of ERG loss. It is apparent that future studies using different dosages and durations of DHA would be of considerable interest.