Essential Fatty Acids
Patients with CF have been reported to have low levels of the essential fatty acids (EFA) linoleic acid (omega-6) and alpha linolenic acid (omega-3). These nutrients are essential components of all cell membranes and are also involved in hormone synthesis and immune function. Deficiencies of the omega-3 long chain polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid are also common (Strandvik et al, 2001). Dietary fat malabsorption contributes to low levels of these essential nutrients. It has also been suggested that deficiency is partly due to a defect in fatty acid metabolism caused by the CFTR mutation itself (Freedman et al, 2004). Although clinical symptoms of EFA deficiency are rare, it is thought that sub-optimal levels may increase the susceptibility to respiratory infections with S. aureus and P. aeruginosa (Lloyd-Still, 2002). To enhance the EFA intake a Mediterranean diet has been recommended for patients with CF. The best source of EFA occurring naturally in the diet is oily fish e.g. salmon and sardines (Strandvik, 2006). Essential fatty acid supplements are not recommended as the most effective dose is unknown, and providing the incorrect balance of the types of EFA may be harmful ( Beckles-Willson et al, 2007;).
• EFA supplements are not recommended as the most effective dose is unknown and providing the incorrect balance of EFA may be harmful
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Freedman SD, Blanco PG, Zaman MN, et al. Association of cystic fibrosis with abnormalities in fatty acid metabolism. N Engl J Med 2004; 350: 560-569. [PubMed]
Lloyd-Still JD. Essential fatty acid deficiency and nutritional supplementation in cystic fibrosis. J Pediatr 2002; 141: 157-159. [PubMed]
Strandvik B, Gronowitz E, Enlund F, et al. Essential fatty acid deficiency in relation to genotype in patients with cystic fibrosis. J Pediatr 2001; 139: 650-655. [PubMed]
Strandvik B. Mediterranean diet and cystic fibrosis. Br J Nutr 2006; 96: 199-200. [PubMed]