Fish oil-fed mice have impaired resistance to influenza infection.
Dietary fish oils, rich in (n-3) PUFA, including eicosapentaenoic acid and docosahexaenoic acid, have been shown to have antiinflammatory properties. Although the antiinflammatory properties of fish oil may be beneficial during a chronic inflammatory illness, the same antiinflammatory properties can suppress the inflammatory responses necessary to combat acute viral infection. Given that (n-3) fatty acid-rich fish oil supplementation is on the rise and with the increasing threat of an influenza pandemic, we tested the effect of fish oil feeding for 2 wk on the immune response to influenza virus infection. Male C57BL/6 mice fed either a menhaden fish oil/corn oil diet (4 g fish oil:1 g corn oil, wt:wt at 5 g/100 g diet) or a control corn oil diet were infected with influenza A/PuertoRico/8/34 and analyzed for lung pathology and immune function. Although fish oil-fed mice had lower lung inflammation compared with controls, fish oil feeding also resulted in a 40% higher mortality rate, a 70% higher lung viral load at d 7 post infection, and a prolonged recovery period following infection. Although splenic natural killer (NK) cell activity was suppressed in fish oil-fed mice, lung NK activity was not affected. Additionally, lungs of infected fish oil-fed mice had significantly fewer CD8+ T cells and decreased mRNA expression of macrophage inflammatory protein-1-alpha, tumor necrosis factor-alpha, and interleukin-6. These results suggest that the antiinflammatory properties of fish oil feeding can alter the immune response to influenza infection, resulting in increased morbidity and mortality.
Schwerbrock
Nicole M J
NM
Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Karlsson
Erik A
EA
Shi
Qing
Q
Sheridan
Patricia A
PA
Beck
Melinda A
MA
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000009:adverse effects*; D003314:Corn Oil / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000009:adverse effects* / Q000494:pharmacology; D005395:Fish Oils / Q000009:adverse effects* / Q000494:pharmacology; D007113:Immunity, Innate / Q000187:drug effects*; D009980:Influenza A virus; D007694:Killer Cells, Natural / Q000378:metabolism; D008168:Lung / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000378:metabolism; D009976:Orthomyxoviridae Infections / Q000276:immunology*; D012333:RNA, Messenger / Q000378:metabolism; D012720:Severity of Illness Index; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013601:T-Lymphocytes / Q000378:metabolism; D019562:Viral Load; D015430:Weight Gain / Q000187:drug effects
D000893:Anti-Inflammatory Agents; D016207:Cytokines; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D012333:RNA, Messenger; D003314:Corn Oil