Relationship between Long Chain n -3 Polyunsaturated Fatty Acids and Autism Spectrum Disorder: Systematic Review and Meta-Analysis of Case-Control and Randomised Controlled Trials

摘要

Omega-3 long chain polyunsaturated fatty acid supplementation ( n -3 LCPUFA) for treatment of Autism Spectrum Disorder (ASD) is popular. The results of previous systematic reviews and meta-analyses of n -3 LCPUFA supplementation on ASD outcomes were inconclusive. Two meta-analyses were conducted; meta-analysis 1 compared blood levels of LCPUFA and their ratios arachidonic acid (ARA) to docosahexaenoic acid (DHA), ARA to eicosapentaenoic acid (EPA), or total n -6 to total n -3 LCPUFA in ASD to those of typically developing individuals (with no neurodevelopmental disorders), and meta-analysis 2 compared the effects of n -3 LCPUFA supplementation to placebo on symptoms of ASD. Case-control studies and randomised controlled trials (RCTs) were identified searching electronic databases up to May, 2016. Mean differences were pooled and analysed using inverse variance models. Heterogeneity was assessed using I 2 statistic. Fifteen case-control studies ( n = 1193) were reviewed. Compared with typically developed, ASD populations had lower DHA (?2.14 [95% CI ?3.22 to ?1.07]; p < 0.0001; I 2 = 97%), EPA (?0.72 [95% CI ?1.25 to ?0.18]; p = 0.008; I 2 = 88%), and ARA (?0.83 [95% CI, ?1.48 to ?0.17]; p = 0.01; I 2 = 96%) and higher total n -6 LCPUFA to n -3 LCPUFA ratio (0.42 [95% CI 0.06 to 0.78]; p = 0.02; I 2 = 74%). Four RCTs were included in meta-analysis 2 ( n = 107). Compared with placebo, n -3 LCPUFA improved social interaction (?1.96 [95% CI ?3.5 to ?0.34]; p = 0.02; I 2 = 0) and repetitive and restricted interests and behaviours (?1.08 [95% CI ?2.17 to ?0.01]; p = 0.05; I 2 = 0). Populations with ASD have lower n -3 LCPUFA status and n -3 LCPUFA supplementation can potentially improve some ASD symptoms. Further research with large sample size and adequate study duration is warranted to confirm the efficacy of n -3 LCPUFA.