Yu-Shian Cheng, Ping-Tao Tseng, Yen-Wen Chen, Brendon Stubbs, Wei-Chieh Yang, Tien-Yu Chen, Ching-Kuan Wu, Pao-Yen Lin

Deficiency of omega 3 fatty acids may be linked to autism spectrum disorder (ASD). Evidence about the potential therapeutic effects of supplementation of omega 3 fatty acids is lacking in ASD patients. We searched major electronic databases from inception to June 21, 2017, for randomized clinical trials, which compared treatment outcomes between supplementation of omega 3 fatty acids and placebo in patients with ASD. An exploratory random-effects meta-analysis of the included studies was undertaken. Six trials were included (n=194). Meta-analysis showed that supplementation of omega 3 fatty acids improved hyperactivity (difference in means =-2.692, 95% confidence interval [CI] =-5.364 to -0.020, P=0.048, studies =4, n=109), lethargy (difference in means =-1.969, 95% CI =-3.566 to -0.372, P=0.016, studies =4, n=109), and stereotypy (difference in means =-1.071, 95% CI =-2.114 to -0.029, P=0.044, studies =4, n=109). No significant differences emerged between supplementation of omega 3 fatty acids and placebo in global assessment of functioning (n=169) or social responsiveness (n=97). Our preliminary meta-analysis suggests that supplementation of omega 3 fatty acids may improve hyperactivity, lethargy, and stereotypy in ASD patients. However, the number of studies was limited and the overall effects were small, precluding definitive conclusions. Future large-scale randomized clinical trials are needed to confirm or refute our findings.