title: 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.
abstract: 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 ofn-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 totaln-6 to totaln-3 LCPUFA in ASD to those of typically developing individuals (with no neurodevelopmental disorders), and meta-analysis 2 compared the effects ofn-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 usingI² 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;I² = 97%), EPA (-0.72 [95% CI -1.25 to -0.18];p= 0.008;I² = 88%), and ARA (-0.83 [95% CI, -1.48 to -0.17];p= 0.01;I² = 96%) and higher totaln-6 LCPUFA ton-3 LCPUFA ratio (0.42 [95% CI 0.06 to 0.78];p= 0.02;I² = 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;I² = 0) and repetitive and restricted interests and behaviours (-1.08 [95% CI -2.17 to -0.01];p= 0.05;I² = 0). Populations with ASD have lowern-3 LCPUFA status andn-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 ofn-3 LCPUFA.
authors.affiliation: Massey Institute of Food Science and Technology, School of Food and Nutrition, Massey University, Auckland 0745, New Zealand. h.mazahery@massey.ac.nz.
authors.forename: Hajar
authors.initials: H
authors.lastname: Mazahery
authors.affiliation: Commonwealth Scientific Industrial Research Organisation (CSIRO) Food, Nutrition and Bioproducts, Adelaide SA 5000, Australia. welma.stonehouse@csiro.au.
authors.forename: Welma
authors.initials: W
authors.lastname: Stonehouse
authors.affiliation: Massey Institute of Food Science and Technology, School of Food and Nutrition, Massey University, Auckland 0745, New Zealand. delshad.maryam@yahoo.com.
authors.forename: Maryam
authors.initials: M
authors.lastname: Delshad
authors.affiliation: Massey Institute of Food Science and Technology, School of Food and Nutrition, Massey University, Palmerston North 4410, New Zealand. m.c.kruger@massey.ac.nz.
authors.forename: Marlena C
authors.initials: MC
authors.lastname: Kruger
authors.affiliation: Massey Institute of Food Science and Technology, School of Food and Nutrition, Massey University, Auckland 0745, New Zealand. c.conlon@massey.ac.nz.
authors.forename: Cathryn A
authors.initials: CA
authors.lastname: Conlon
authors.affiliation: Massey Institute of Food Science and Technology, School of Food and Nutrition, Massey University, Auckland 0745, New Zealand. k.l.beck@massey.ac.nz.
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Beck
authors.affiliation: Massey Institute of Food Science and Technology, School of Food and Nutrition, Massey University, Auckland 0745, New Zealand. p.r.vonhurst@massey.ac.nz.
authors.forename: Pamela R
authors.initials: PR
authors.lastname: von Hurst
mesh_terms: D016718:Arachidonic Acid / Q000008:administration & dosage / Q000097:blood; D000067877:Autism Spectrum Disorder / Q000097:blood* / Q000188:drug therapy; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood*; D006801:Humans; D016032:Randomized Controlled Trials as Topic
chemical_list: D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid
keywords: autism; concentration; intervention; long chain polyunsaturated fatty acids; meta-analysis; omega-3; symptoms