Dose-related effects of eicosapentaenoic acid on innate immune function in healthy humans: a comparison of young and older men.
BACKGROUND
Increasing intakes of long-chain n-3 polyunsaturated fatty acids (PUFAs) can decrease markers of immunity. However, dose- and age-related responses have not been identified.


OBJECTIVE
The objective was to determine the effects of different amounts of eicosapentaenoic acid (EPA) on innate immune outcomes in young and older males.


METHODS
In a controlled, double-blind study, healthy young and older men consumed 1 of 4 supplements provided as capsules: placebo (corn oil) or different amounts of an oil providing 1.35, 2.7, or 4.05 g EPA/d for 12 wk. Blood samples were collected at baseline and after 12 wk.


RESULTS
EPA was incorporated in a linear dose-response fashion into plasma and mononuclear cell (MNC) phospholipids; incorporation was greater in the older men. EPA treatment did not alter neutrophil or monocyte phagocytosis, monocyte respiratory burst, or the production of inflammatory cytokines by MNCs in the young or older men. EPA treatment caused a dose-dependent decrease in neutrophil respiratory burst only in the older men. Increased incorporation of EPA into plasma or MNC phospholipids was associated with decreased production of prostaglandin E2 by MNCs from both young and older men.


CONCLUSIONS
Older subjects incorporate EPA into plasma and MNC phospholipids more readily than do younger subjects. Other than prostaglandin E2 production, innate immune responses in young subjects are not affected by an EPA intake of < or =4.05 g/d. Older subjects are more sensitive to the immunologic effects of EPA, and the neutrophil respiratory burst is lower at higher EPA intakes.
The Rowett Research Institute, Aberdeen, United Kingdom.
Dinka
D
Rees
Elizabeth A
EA
Miles
Tapati
T
Banerjee
Solenne J
SJ
Wells
Catherine E
CE
Roynette
Klaus Wj
KW
Wahle
Philip C
PC
Calder
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology* / Q000502:physiology; D000704:Analysis of Variance; D016207:Cytokines / Q000096:biosynthesis; D019587:Dietary Supplements; D015232:Dinoprostone / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects
D016207:Cytokines; D010743:Phospholipids; D015118:Eicosapentaenoic Acid; D015232:Dinoprostone