Biological effects of a dietary omega-3 polyunsaturated fatty acids supplementation in cystic fibrosis patients: a randomized, crossover placebo-controlled trial.
Study design (if review, criteria of inclusion for studies)
2 x 6-month period, cross-over trial with no washout period.
Participants
17 children and young adults with CF and pancreatic insufficiency (mean (SD) age 18 (9) years)), 10 male and 7 female. 1 participant discontinued study after 8 months for personal convenience.
Interventions
Liquid dietary supplement containing PUFA mixture (EPA, DHA, GLA and STA) compared with liquid dietary supplement without PUFA mixture over 6 months. Volume of supplementation was determined according to participant's weight; intake ranged from 100 - 300
Outcome measures
number of people experiencing adverse events; number of deaths; changes in peripheral blood neutrophil membrane composition; in vitro neutrophilic response to inflammatory stimuli; changes in in-vitro neutrophil chemotaxis.
Main results
Increase in eicosapentaenoic acid was observed in neutrophil membrane following omega-3 PUFA dietary supplementation (from 0.7+/-0.6 to 1.6+/-0.6 micromol%, P<0.01). The leukotriene B(4) (LTB(4))/leukotriene B(5) (LTB(5)) ratio was decreased (from 72+/-27 to 24+/-7, P<0.001) in CF patients taking omega-3 PUFA supplements. In contrast, omega-3 PUFA supplementation affected neither internalization of IL-8 receptors following IL-8 exposure, nor IL-8-induced neutrophil chemotaxis.
Authors' conclusions
Our results show that omega-3 PUFA are incorporated in neutrophil membranes. The subsequent decrease in LTB(4)/LTB(5) ratio suggests that, in such conditions, neutrophils may produce less pro-inflammatory mediators from the acid arachidonic pathway. These data indicate that omega-3 PUFA intake may have anti-inflammatory effect that still need to be assessed by long-term studies following large groups of patients.