Background: Epidemiological (population studies) and other studies suggest that a diet rich in omega-3 essential fatty acids (derived from fish oil) may have beneficial anti-inflammatory effects for chronic conditions such as cystic fibrosis.
Objectives: To determine whether there is evidence that omega-3 polyunsaturated fatty acid supplementation reduces morbidity and mortality. To identify any adverse events associated with omega-3 polyunsaturated fatty acid supplementation.
Search strategy: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group specialised trials register, which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings. Authors and persons interested in the question were contacted. Date of the most recent search of the Group's specialised register: May 2002.
Selection criteria: Randomised controlled trials in patients with cystic fibrosis in which omega-3 fatty acid supplements were compared with a placebo oil.
Data collection and analysis: Two reviewers independently selected the trials to be included in the review and assessed the methodological quality of the trials using two approaches: Cochrane assessment of allocation concealment and Jadad quality assessment score. Using data acquisition forms, two reviewers independently extracted data. Missing data has been requested.
Main results: The initial literature search identified six trials. Two trials, involving 31 participants satisfied our inclusion criteria and were included in the review. Both compared omega-3 fatty acids to olive oil controls for a six week treatment period. One study (19 participants) showed an improvement in FEV1, FVC, Shwachman score and reduction in sputum volume in the fish oil group at the end of this short treatment period.
Reviewer's conclusions: The review of trials found that regular omega-3 supplements may provide some benefits for people with cystic fibrosis with relatively few adverse effects, although the evidence is insufficient to draw firm conclusions. There is insufficient evidence to recommend routine use of supplements of omega-3 fatty acids in people with cystic fibrosis. The most notable feature highlighted by this review was the lack of data for many of the outcomes likely to be meaningful to people with or making treatment decisions about CF. A large, long-term, multi-centre, randomised controlled study is needed in order to determine if there is a significant therapeutic effect and to assess the influence of disease severity, dosage and duration of treatment. Future researchers should note the need for additional pancreatic enzymes.