The ratio of dietary (n-6) to (n-3) fatty acids influences immune system function, eicosanoid metabolism, lipid peroxidation and vitamin E status in aged dogs.

TitleThe ratio of dietary (n-6) to (n-3) fatty acids influences immune system function, eicosanoid metabolism, lipid peroxidation and vitamin E status in aged dogs.
Publication TypeJournal Article
Year of Publication1997
AuthorsWander RC, Hall JA, Gradin JL, Du SH, Jewell DE
JournalThe Journal of nutrition
Volume127
Issue6
Pagination1198-205
Date Published1997 Jun
ISSN0022-3166
KeywordsAging, Animals, Dietary Fats, Dinoprostone, Dogs, Dose-Response Relationship, Drug, Eicosanoids, Fatty Acids, Omega-3, Fatty Acids, Omega-6, Fatty Acids, Unsaturated, Female, Immune System, Lipid Peroxidation, Vitamin E
Abstract

We studied the effects of feeding experimental diets containing (n-6) to (n-3) fatty acid ratios of 31:1, 5.4:1, and 1.4:1 to 20 healthy female geriatric Beagles (9.5-11.5 y) for 8-12 wk on various indices of the immune response. Compared with the 31:1 diet, consumption of the 5.4:1 and 1.4:1 diets significantly increased (n-3) fatty acids in plasma (2.17 +/- 0.64, 9.05 +/- 0.64, 17.46 +/- 0.64 g/100 g fatty acids, respectively, P < 0.0001). Although supplementation with (n-3) fatty acids did not significantly alter the humoral immune response to keyhole limpet hemocyanin (KLH), it significantly suppressed the cell-mediated immune response based on results of a delayed-type hypersensitivity (DTH) skin test. The DTH response after intradermal injection of KLH at 24 h was significantly lower in the group consuming the 1.4:1 diet compared with the group consuming the 5.4:1 (P = 0.02) or the 31:1 diets (P = 0.04), and remained significantly suppressed at 48 h in the group fed 1.4:1 relative to the group fed 31:1. After consumption of the 1.4:1 diet, stimulated mononuclear cells produced 52% less prostaglandin E2 (PGE2) than those from dogs fed the 31:1 diet (224 +/- 74 and 451 +/- 71 pmol/L, respectively, P = 0.04). Plasma concentration of alpha-tocopherol was 20% lower in dogs fed the 1.4:1 diet compared with those fed the 31:1 diet (P = 0.04), and lipid peroxidation was greater in both plasma (P = 0.03) and urine (P = 0.002). These data suggest that although a ratio of dietary (n-6) to (n-3) fatty acids of 1.4:1 depresses the cell-mediated immune response and PGE2 production, it increases lipid peroxidation and lowers vitamin E concentration.

Alternate JournalJ. Nutr.