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Omega-3 fatty acids for cystic fibrosis

  • Review
  • Intervention




Studies suggest that a diet rich in omega-3 essential fatty acids may have beneficial anti-inflammatory effects for chronic conditions such as cystic fibrosis.


To determine whether there is evidence that omega-3 polyunsaturated fatty acid supplementation reduces morbidity and mortality and to identify any adverse events associated with supplementation.

Search methods

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising 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 last search: 10 March 2011.

Selection criteria

Randomised controlled trials in people with cystic fibrosis comparing omega-3 fatty acid supplements with placebo.

Data collection and analysis

Two authors independently selected studies for inclusion, extracted data and assessed the risk of bias of the studies.

Main results

The searches identified 13 studies; four studies with 91 participants were included. Two studies compared omega-3 fatty acids to olive oil for six weeks. One study compared a liquid dietary supplement containing omega-3 fatty acids to one without for six months. One study compared omega-3 fatty acids and omega-6 fatty acids to a control (capsules with customised fatty acid blends) for three months. Only one short-term study (19 participants) comparing omega-3 to placebo reported a significant improvement in lung function and Shwachman score and a reduction in sputum volume in the omega-3 group. Another study (43 participants) demonstrated a significant increase in serum phospholipid essential fatty acid content and a significant drop in the n-6/n-3 fatty acid ratio following omega-3 fatty acid supplementation compared to control. The longer-term study (17 participants) demonstrated a significant increase in essential fatty acid content in neutrophil membranes and a significant decrease in the leukotriene B4 to leukotriene B5 ratio in participants taking omega-3 supplements compared to placebo.

Authors' conclusions

This review found that regular omega-3 supplements may provide some benefits for people with cystic fibrosis with relatively few adverse effects, although evidence is insufficient to draw firm conclusions or recommend routine use of these supplements in people with cystic fibrosis. This review has highlighted the lack of data for many outcomes meaningful to people with or making treatment decisions about cystic fibrosis. A large, long-term, multicentre, randomised controlled study is needed to determine any 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

The use of omega-3 supplements in people with cystic fibrosis

Cycles of infection and inflammation are believed to worsen lung function in people with cystic fibrosis. Studies suggest that omega-3 fatty acids, such as those derived from fish oils, may be anti-inflammatory and may benefit many chronic inflammatory diseases including cystic fibrosis. This review includes four small studies with a total of 91 participants which compare omega-3 supplements to placebo. One short-term study reported that lung function and clinical status improved significantly when taking omega-3 supplements. Patients also produced significantly less sputum when taking omega-3 supplements. Two longer studies showed significant increases in essential fatty acid content of white blood cell membranes and serum phospholipids in people taking omega-3 supplements. Few adverse effects were reported in any of the studies. We conclude that regular omega-3 supplements may benefit people with cystic fibrosis with few adverse effects. However, there is not enough evidence from the four small studies included in this review to draw firm conclusions or recommend routine use of these supplements in people with cystic fibrosis. Larger and longer trials are needed to assess the clinical benefit of omega-3 supplementation and to determine the appropriate dosage.

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