Special diets have little impact on autism traits, according to a recent review of data from 27 clinical trials. While many families with autistic children ask their doctors about these dietary interventions in hopes that they might relieve certain autism traits, such as repetitive behaviors, the analysis found little to no scientific evidence to support the diets.
The new research was led by Mara Paradella, a professor of psychiatry at the Complutense University of Madrid in Spain. According to a Spectrum News report this month, Paradella said she and her colleagues began their research after they observed how many dietary interventions families were trying and hoped to document the benefits (or lack thereof).
To carry out their study, the researchers searched three large international databases – Ovid Medline, Embase, and PsychINFO – for clinical trials of dietary interventions for autism. Their final analysis covered 27 studies and 1,028 people with autism between 2 and 60 years old. About half of the participants had received dietary interventions, while the rest received placebos.
Paradella and her team grouped the diets into those with added supplements, and those that eliminated certain types of food. They then evaluated the impact of those diets on autism traits like repetitive behaviors, anxiety, and impulsivity. Ultimately, they found that only Omega-3 and vitamin supplements had any effect in relieving these symptoms. The study’s findings were published on October 4, 2019 in the journal Pediatrics.
The researchers also found that 75% of the studies did not account for participants food intolerances or existing nutritional deficiencies. The trials also spanned different age groups, making it difficult to determine at what age participants responded best.
Zachary Warren, an associate professor at Vanderbilt University in Nashville, Tennessee, said he views the study as “a call for better designed clinical trials.” Warren was not involved in the study.
The same behavioral intervention doesn’t have the same effect in pubertal children versus very young children,” Parellada was quoted as saying by Spectrum. “We need to do more to study nutritional interventions in very young children as well.”