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.  Thienprasert et al., 2009 [221]  Children (9–12 years)RCT  EPA (200 mg) + DHA (1 g)  Fewer episodes (p = 0.014) and shorter duration (p = 0.024) of illness in fish oil group. TGF-β1 concentration was lower in fish oil group (p < 0.001).