Effect of CLA supplementation on immune function in young healthy volunteers.
OBJECTIVE
This study investigated the effect of dietary CLA supplementation (3g/day; 50:50 mix of the two major isomers) on the immune system and plasma lipids and glucose of healthy human (male and female) volunteers.


METHODS
Double-blind, randomized, reference-controlled study. SUBJECT AND INTERVENTION: A total of 28 healthy male and female participants aged 25-50 y received either high oleic sunflower oil (reference) or 50% CLA 9-11 and 50% CLA 10-12 CLA isomers (50:50 CLA-triglyceride form). The treatments were given as supplements in soft-gel capsules providing a total 3 g (6 x 500 mg capsules) per day in treatment groups for 12 weeks. A 12-week washout period followed the intervention period.


RESULTS
Levels of plasma IgA and IgM were increased (P < 0.05 and 0.01 respectively), while plasma IgE levels were decreased (P < 0.05). CLA supplementation also decreased the levels of the proinflammatory cytokines, TNF-alpha and IL-1beta (P < 0.05), but increased the levels of the anti-inflammatory cytokine, IL-10 (P < 0.05). Another aspect of immune function, delayed type hypersensitivity (DTH) response, was decreased during and after CLA supplementation (P < 0.05). However, plasma glucose, lipids, lymphocyte phenotypic results were not affected significantly by CLA.


CONCLUSIONS
This is the first study to show that CLA, a fatty acid naturally found in dairy and meat products, can beneficially affect immune function in healthy human volunteers.


BACKGROUND
This study was supported by Loders-Croklaan, The Netherlands and SEERAD (Scottish Executive Environmental Rural and Agriculture Department).
Song
H-J
HJ
Rowett Research Institute, Aberdeen, UK.
Grant
I
I
Rotondo
D
D
Mohede
I
I
Sattar
N
N
Heys
S D
SD
Wahle
K W J
KW
D000328:Adult; D001786:Blood Glucose / Q000187:drug effects; D002097:C-Reactive Protein / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed; D007109:Immunity / Q000187:drug effects* / Q000502:physiology; D007136:Immunoglobulins / Q000097:blood / Q000187:drug effects; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D008055:Lipids / Q000097:blood; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D012016:Reference Values; D012737:Sex Factors; D013997:Time Factors
D001786:Blood Glucose; D016207:Cytokines; D007136:Immunoglobulins; D044243:Linoleic Acids, Conjugated; D008055:Lipids; D002097:C-Reactive Protein