Boys diagnosed with autism had more than triple the odds of being exposed daily to either diet soda itself or comparable doses of aspartame from multiple sources. Child exposure would have occurred in the womb after maternal consumption of artificial sweeteners during pregnancy or from breastfeeding (which has been shown to contain multiple and potentially toxic synthetic sweetener metabolites). The six authors in this study also reviewed large-scale studies finding the use of diet drinks or aspartame in pregnancy increased a variety of other adverse health outcomes. This included a 38% increase in preterm birth (less than 37 weeks) and a 67% increase in early preterm birth (less than 32 weeks). Among mothers with gestational diabetes (which affects approximately 8% of U.S. pregnancies), there was nearly a doubling of risk their child would be overweight/obese by age 7. These findings are of great concern as 24-30% of all pregnant women reported using non-nutritive sweeteners or diet soda during pregnancy.
Since its introduction, aspartame-the leading sweetener in U.S. diet sodas (DS)-has been reported to cause neurological problems in some users. In prospective studies, the offspring of mothers who consumed diet sodas/beverages (DSB) daily during pregnancy experienced increased health problems. We hypothesized that gestational/early-life exposure to ≥1 DS/day (DSearly) or equivalent aspartame (ASPearly: ≥177 mg/day) increases autism risk. The case-control Autism Tooth Fairy Study obtained retrospective dietary recalls for DSB and aspartame consumption during pregnancy/breastfeeding from the mothers of 235 offspring with autism spectrum disorder (ASD: cases) and 121 neurotypically developing offspring (controls). The exposure odds ratios (ORs) for DSearly and ASPearly were computed for autism, ASD, and the non-regressive conditions of each. Among males, the DSearly odds were tripled for autism (OR = 3.1; 95% CI: 1.02, 9.7) and non-regressive autism (OR = 3.5; 95% CI: 1.1, 11.1); the ASPearly odds were even higher: OR = 3.4 (95% CI: 1.1, 10.4) and 3.7 (95% CI: 1.2, 11.8), respectively (p < 0.05 for each). The ORs for non-regressive ASD in males were almost tripled but were not statistically significant: DSearly OR = 2.7 (95% CI: 0.9, 8.4); ASPearly OR = 2.9 (95% CI: 0.9, 8.8). No statistically significant associations were found in females. Our findings contribute to the growing literature raising concerns about potential offspring harm from maternal DSB/aspartame intake in pregnancy.