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Omega-3 fatty acids (from fish oils) for cystic fibrosis

  • Review
  • Intervention

Authors

  • NNR Beckles-Willson,

  • T Elliott,

  • MML Everard


Mrs Tracy N'Diaye, Research Manager, Research Office, Sheffield Children's Hospital, 16 Northumberland Road, Sheffield, South Yorkshire, S10 2TH, UK. tracy.ndiaye@sch.nhs.uk.

Abstract

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 trials register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Authors and persons interested in the subject of the review were contacted.

Date of the most recent search: August 2004.

Selection criteria

Randomised controlled trials in people 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 studies to be included in the review and assessed the methodological quality of the studies using two approaches: Cochrane assessment of allocation concealment and Jadad quality assessment score. Using data acquisition forms, two reviewers independently extracted data. Missing data have been requested.

Main results

The initial literature search identified six studies. Two studies, 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 forced expiratory volume in one second, forced vital capacity, Shwachman score and reduction in sputum volume in the fish oil group at the end of this short treatment period. These results were not reported in the other study.

Authors' conclusions

The review of studies 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 cystic fibrosis. A large, long-term, multicentre, 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.

Plain language summary

Plain language summary

There is not enough evidence on the safety and effectiveness of fish oil supplements for people with cystic fibrosis

Cycles of infection and inflammation are believed to exacerbate lung damage in people with cystic fibrosis (CF). Fish oils are the richest dietary source of omega-3 fatty acids, which studies suggest may be anti-inflammatory and benefit many chronic inflammatory diseases including CF. This review found regular omega-3 supplements may benefit people with CF with few adverse effects. There is insufficient evidence to draw firm conclusions or recommend routine use of these supplements in people with CF. Larger and longer trials are needed to assess the clinical benefit of fish consumption and/or fish oil supplementation and to determine appropriate dosage.

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