Fish oil n-3 polyunsaturated fatty acids selectively affect plasma cytokines and decrease illness in Thai schoolchildren: a randomized, double-blind, placebo-controlled intervention trial.

OBJECTIVE: To determine whether very long-chain n-3 polyunsaturated fatty acids (PUFAs) affect illness and selected plasma cytokines in schoolchildren. STUDY DESIGN: Thai schoolchildren aged 9 to 12 years consumed milk containing placebo (soybean) oil (n = 86) or fish oil (n = 94) on 5 days per week for 6 months; the latter provided 200 mg eicosapentaenoic acid plus 1 g docosahexaenoic acid daily. Episodes and duration of illness were recorded, and plasma interleukin (IL)-2 receptor, IL-6, IL-10, and transforming growth factor (TGF)-beta1 concentrations and the fatty acid profile of plasma phosphatidylcholine determined. RESULTS: After intervention, very long-chain n-3 PUFAs were higher in plasma phosphatidylcholine in the fish oil group than in the placebo group (P < .001). The fish oil group showed fewer episodes (P = .014) and shorter duration (P = .024) of illness (mainly upper respiratory tract) than the placebo group. Plasma IL-2 receptor, IL-10, and IL-6 were not affected by either treatment. Plasma TGF-beta1 increased in both groups, but the increase was smaller in the fish oil group, and at the end of supplementation TGF-beta1 concentration was lower in the fish oil group (P < .001). CONCLUSIONS: Very long-chain n-3 PUFAs reduce illness, mainly infections, in healthy Thai schoolchildren.

The effect of docosahexaenoic acid on aggression in elderly Thai subjects--a placebo-controlled double-blind study.

Docosahexaenoic acid (DHA) administration controls extraggression (aggression against others) in young subjects under psychological stress. However, it is not known whether its administration affects extraggression of elderly subjects. Forty Thai subjects of 50-60 years of age (22 males and 18 females) were recruited from Silpakorn University and nearby villages. They were allocated to the control and DHA groups in a double-blind fashion, and took 10 mixed plant oil capsules and 10 DHA capsules (1.5g DHA/day) for 2 months, respectively. Extraggression was measured with a psychological test (PF Study) at the beginning and end of the study. Just prior to the PF Study at the end of the study, subjects were asked to watch a stressful videotape as a stressor component. The average DHA intake from food was 150-160mg/day. In the group of university employees, extraggression did not change over time with placebo, whereas extraggression significantly decreased (31 +/- 13 to 24 +/- 13%, P = 0.04 by the paired-t test, P = 0.04 by ANOVA). In the group of villagers, there was no significant difference between the control and DHA groups in extraggression. The DHA administration favorably controlled extraggression in at least elderly white-collar workers. The daily intake of 150-160 mg/day of DHA was not enough to control extraggression.