Maternal Dietary Factors and the Risk of Autism Spectrum Disorders: A Systematic Review of Existing Evidence

Abstract

Prenatal maternal diet is a critical factor in offspring neurodevelopment. Emerging evidence suggests that prenatal diet may also play a role in the etiology autism spectrum disorder (ASD). This review summarizes studies published in English that examined prenatal nutrients or maternal diet in association with ASD from PubMed as of July 2020. Thiry-six studies from nine countries were included in this systematic review; these focused on multivitamin (n = 5), prenatal vitamin (n = 3), folic acid (FA; n = 14), Vitamin D (n = 11), polyunsaturated fatty acid or fish/supplement intake (n = 7), iron (n = 3), Vitamin B12 (n = 1), calcium (n = 1), magnesium (n = 1), and broad maternal dietary habits (n = 3). Overall, higher or moderate intake of prenatal/multivitamin, FA, and Vitamin D was associated with reductions in odds of ASD, though results have not been uniform and there is a need to clarify differences in findings based on biomarkers versus reported intake. Evidence was inconclusive or insufficient for other nutrients. Differences in the timing and measurement of these dietary factors, as well as potential residual confounding, may contribute to existing discrepancies. Key areas for future research to better understand the role of maternal diet in ASD include the need to address potential critical windows, examine the combined effect of multiple nutrients, and consider interactions with genetic or environmental factors.

Mitochondria May Mediate Prenatal Environmental Influences in Autism Spectrum Disorder

“…Studies have associated an increased risk of ASD with atypical pre- and postnatal Zn and Cu metabolism [ 26 ] and found that atypical levels of essential (Zn, Mn) and non-essential (Pb) metals during prenatal development and early life in individuals with ASD are associated with long-term physiological and developmental alternations [ 27 ]. Studies have associated low maternal iron (Fe) with increased ASD risk [ 28 ]. Prenatal Zn and Cu are essential for the function of the cytoplasmic superoxide dismutase (SOD) which is essential for controlling cellular oxidative stress, while Cu is essential for ETC complex IV function.…”

Maternal Dietary Patterns during Pregnancy and Child Autism-Related Traits: Results from Two US Cohorts

“…ASD has a complex etiology, with both genetic and environmental contributors [2], and evidence for prenatal origins [3]. Research has linked maternal prenatal diet with ASD [4][5][6], with most of this work focused on a small number of individual nutrients and foods [4][5][6][7][8][9][10][11][12][13]. The majority of studies have suggested inverse associations with ASD, particularly for folic acid and vitamin D levels, though conflicting findings exist [5,6,[14][15][16][17][18][19][20][21][22][23][24].…”

Dynamic and Systemic Perspective in Autism Spectrum Disorders: A Change of Gaze in Research Opens to A New Landscape of Needs and Solutions

“…Many risks and protective factors have been linked to the onset of ASD in the offspring, providing suggestions for clinical practice. Numerous studies focusing on the risk of ASD in the offspring demonstrate the relevance of carefully designed maternal diet, including nutraceutical supplementation [ 50 , 225 ], the prevention and treatment of metabolic abnormalities [ 226 ], avoidance of some toxicant exposure [ 227 ]. However, there is a striking discrepancy between the plethoric literature in this field and the scarce transfer of knowledge to clinical practice.…”