Non-specific effect of omega-3 fatty acid supplementation on autistic spectrum disorder: systematic review and meta-analysis

ABSTRACT

Background/objectives: The evidence on the effects of polyunsaturated fatty acid supplementation in the treatment of symptoms of autistic spectrum disorder (ASD) remains limited. In this paper, we summarize the effects reported in interventional studies that use omega-3 supplementation in children and adolescents with ASD.

Methods

We searched seven databases and found 13 eligible controlled trials that use omega-3 supplementation in children and adolescents with ASD.

Data extraction: We collected details on study design, intervention time, supplement dosage, and the autism assessment scale. Meta-analyses and subgroup analysis were conducted according to the autism symptoms.

Results

Omega-3 and omega-6 supplementation improved ASD symptoms according to the Aberrant Behavior Checklist (standard mean difference - SMD = -0.13; CI 95% = -0.34, -0.02). However, using subgroup analysis, we observed no efficacy in terms of improvements in hyperactivity (SMD = -0.03; CI 95%: -0.43, 0.36), irritability (SMD = -0.18; CI 95%: -0.51, 0.15), stereotypy (SMD = -0.03; CI 95%: -0.43, 0.36), inappropriate speech (SMD = -0.68; CI 95%: -1.49, 0.14), lethargy (SMD = -0.22; CI 95%: -0.58, 0.14), and social function (SMD = -0.71; IC 95%: -1.56, 0.14). W-3 and w-6 supplementation also showed no efficacy according to the Social Responsiveness Scale (SMD = 0.08; CI 95%: -0.23, 0.39). The adverse effects were classified as mild and equally distributed between the placebo and intervention groups.

Conclusions

Despite w-3 and w-6 supplementation showing minimal beneficial effects in the treatment of autism, the subgroup analyses indicated that there is a lack of evidence on the beneficial role of w-3 and w-6 in treating ASD.

Systematic Review Registration: PROSPERO number CRD42020146116.

KEYWORDS:

• Essential fatty acids
• autistic spectrum disorder
• supplementation
• systematic review and meta-analysis
• complementary and alternative medicine
• neurobiology
• omega-3

Acknowledgements

None.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Declaration of interest

The authors have no relevant interests to declare.

Additional information

Notes on contributors

Kelma de Andrade Wobido

KAW and collected the data and drafted the manuscript. JMS, SSM and DCGS revised the manuscript. MSBC revised the manuscript and analyzed the data. MP contributed to the conception of the work, drafted, revised the manuscript and supervised the study process. The authors approved the final version of the manuscript for publication.

Kelma de Andrade Wobido Nutrition's student at Center for Biological and Health Sciences, Federal University of Western Bahia. Interested in studies on nutrition and autism

Marcela de Sá Barreto da Cunha

Marcela de Sá Barreto da Cunha Professor, Center for Biological and Health Sciences, Federal University of Western Bahia. She has experience in the area of Nutrition, with emphasis on Nutrition Biochemistry, working on the following topics: micronutrient metabolism, antioxidants and oxidative stress, cerrado fruits, phytochemicals, aging and nutrigenomics.

Samilly Silva Miranda

Samilly Silva Miranda Adjunct Professor at the Collective Health Institute - UFBA. PhD in Public Health from the State University of Feira de Santana (UEFS). Master in Public Health from UEFS (2014-2016). Her current projects focus on Metabolic Syndrome, oral condition and quality of life.

Jerusa da Mota Santana

Jerusa da Mota Santana PhD in Public Health (2017), Master in Food, Nutrition and Health, concentration area: Food and Nutritional Security (2014). Graduated in Nutrition (2011). She is currently an Adjunct Professor at the School of Nutrition at the Universidade Federal do Recôncavo da Bahia. She is a researcher in cohort and intervention studies with pregnant women and children up to six months of age. She has experience in the areas: Collective Health, Epidemiology, Food and Nutritional Security and Maternal and Child Health.

Danielle Cristina Guimarães da Silva

Danielle Cristina Guimarães da Silva Professor, Center for Biological and Health Sciences, Federal University of Western Bahia. Has a Ph.D. in Nutrition at Universidade Federal de Viçosa (2017). Has experience in the area of Nutrition, with emphasis on Clinical Nutrition and Social Nutrition

Marcos Pereira

Marcos Pereira Adjunct Professor of Epidemiology at the Institute of Collective Health at the Federal University of Bahia. PhD in Public Health / Epidemiology by the Institute of Collective Health of the Federal University of Bahia (UFBA). Master in Food, Nutrition and Health – UFBA, concentration in Epidemiology of Nutritional Disorders and Public Policies (2014). Graduated in Nutrition from the Federal University of Recôncavo da Bahia (2011). He was an adjunct professor of Epidemiology / Biostatistics at the Medicine Course at the Federal University of Western Bahia. Reviewer of national and international journals. Has in the areas of Collective Health and Nutrition, highlighted in the following themes: Epidemiology and Prevention of HIV / AIDS and other Communicable Infections, Health of Women and Children, Epidemiology in Health Services and Health Inequalities