Children with autism who take supplements of vitamins and omega-3 fatty acids may have fewer symptoms than kids who don't, a research review suggests.
Researchers examined data from 27 trials involving a total of 1,028 children with autism spectrum disorder. Kids were randomly selected to take various dietary supplements, including vitamins or omega-3s, or to take a dummy pill instead.
Omega-3s and vitamin supplements were more effective than the placebo pill at improving several symptoms, functions, and clinical domains, researchers report in Pediatrics. Gains varied in the trials but included improved language and social skills, reduced repetitive behaviours, improved attention, less irritability and behaviour difficulties, and better sleep and communication.
"These results suggest that some dietary interventions could play a role in the clinical management of some areas of dysfunction specific to ASD," said Dr David Fraguas, lead author of the study and a researcher at Hospital General Universitario Gregorio Maranon and Universidad Complutense de Madrid in Spain.
Even though the analysis was based on controlled experiments - the gold standard for testing the effectiveness of medical interventions - the individual studies were too varied in what supplements they tested and how they measured results to draw any broad conclusions about what type or amount of supplements might be ideal for children with autism, researchers note in Pediatrics.
"The underlying mechanisms involved in the potential efficacy of dietary interventions in autism spectrum disorder are unknown, Fraguas said by email. "Our study does not assess this important question and current literature is inconclusive."
About one in 59 kids have autism spectrum disorder, according to the U.S. Centers for Disease Control and Prevention. It's much more often diagnosed in boys than in girls.
Early symptoms of autism can vary but may include repetitive behaviours like hand flapping or body rocking, extreme resistance to changes in routine, and sometimes aggression or self-injury. Behavioural, educational, speech and language therapy may help reduce the severity of symptoms in some children.
There are no medications that can cure autism or treat the main symptoms, but there are some drugs that can help children function better by improving symptoms like inattention, hyperactivity, depression, or seizures, according to the CDC.
While some therapists treating kids with autism advise parents to put children on special diets, rigorous scientific studies haven't proven that there's a good approach to recommend to all kids with autism, according to the CDC.
Complicating matters, children with autism may have a range of health issues related to food, according to the Academy of Nutrition and Dietetics. They may, for example, be sensitive to the taste, smell, colour, or texture of certain foods and eat a very limited selection of items or have difficulty focusing on meals. They might also be prone to constipation, or have medication interactions that impact their appetite.
Kids with autism shouldn't go on a special diet without first seeing a registered dietician nutritionist to ensure they're getting enough nutrients and calories to thrive, AND advises.
Even though vitamin and omega-3 supplements appeared to help children with autism in the current study, Fraguas agreed it's premature to advise parents to start giving kids these supplements.
"Currently, we cannot make a specific recommendation regarding dietary interventions as treatments for autism spectrum disorder," Fraguas said.