Exposure to toxic pesticides in the womb may not actually be linked to autism symptoms, a new study suggests.
With autism now affecting one in 31 American children, a sharp increase from one in 150 in the early 2000sexperts search for possible causes and screening tools to detect the condition earlier.
Among the most studied are environmental pollution and the use of pesticides used in agriculture that infiltrate the food supply, especially fruits and vegetables.
Scientists have long suspected that these chemicals cause inflammation in the brain and alter the levels of neurotransmitters such as dopamine and serotonin, leading to hallmark features such as communication problems and hyperactivity.
In a new study examining pairs of mothers and children exposed during pregnancy to organophosphate pesticides, which are known to be toxic to humans, researchers from NYU Langone in New York City found no significant relationship between the toxins and autism-related traits in their children.
It’s unclear what exactly led to the results, but the researchers suggested that the benefits of a diet high in fruits and vegetables, such as reduced inflammation, may offset the potential harm of pesticides.
The team said that while the findings do not conclusively prove that pesticides are safe for children and pregnant women, they do suggest that pesticides and autism may not be linked.
They noted that future studies could help inform policies and restrictions around pesticides, which have also been linked to neurological disorders such as Parkinson’s disease and several forms of cancer.
Researchers in New York have found that pesticides, long linked to autism, may not cause the condition’s hallmark features (stock image)
“While we know that organophosphate pesticides can be harmful to the developing brain, at the relatively low exposure levels we observed, they were not a major driver of the features seen in autism,” says Dr.
‘These results should not be interpreted as a sign that such pesticides are safe, nor do they rule out autism-related risks at higher exposure or among more vulnerable groups.’
The study, published in JAMA Pediatricslooked at data from 3,339 pairs of mothers and children enrolled at 20 medical centers in the U.S. National Institutes of Health’s Environmental Influences on Child Health Outcomes (ECHO) Program, a nationwide study that examines the impact of environmental, social and biological factors on a child’s health.
The researchers measured the levels of metabolites, byproducts of chemical breakdown in the body, in urine samples during pregnancy. The tests showed that 99 percent of mothers had detectable levels of organophosphate pesticides in their urine.
The team then looked for links between metabolite levels and how the children scored on the Social Responsiveness Scale, a 65-item questionnaire designed to identify social communication difficulties and autism-related traits, such as avoiding eye contact, difficulty understanding people’s emotions and the need to follow specific routines.
Children were assessed to be between five and seven years old on average.
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There were no consistent associations between the levels of metabolites detected in urine and autism-related traits when adjusting for gender and dietary factors, the study found.
The authors note that one limitation is that metabolites are short-lived in the human body, so exact levels can vary over time. Additionally, individual metabolism can influence levels.
This means the markers may not provide the full picture of pesticide exposure, but additional studies could strengthen the findings.
“Our results show that there is still much more to learn about autism,” said Dr. Akhgar Ghassabian, senior study author and associate professor in the department of pediatrics at NYU Grossman School of Medicine.
‘Careful long-term research can help clarify which environmental exposures matter most so that communities and policymakers can make better-informed decisions.’
