Neurotoxins in pesticides, ultraprocessed foods, heavy metals and plastic packaging can harm brain development and mental function in teens, children — even babies in utero — according to a review combining the findings of more than 400 studies. The report was published in Neuroscience & Biobehavioral Reviews.

Chemicals in the food and drinks that young people consume daily are likely fueling the global decline in mental health, according to the authors of a report published in Neuroscience & Biobehavioral Reviews.

Neurotoxins in pesticides, ultraprocessed foods, heavy metals and microplastics can destabilize the nervous system and “lead to a greater experience of stress and impact on social behavior,” Tara Thiagarajan, Ph.D., founder and chief scientist of the nonprofit Sapien Labs and one of the study’s co-authors, told The Defender.

“Think about the analogy of a car,” she said. “A better-made car will better withstand the road bumps, whereas one where the joints are giving way is more likely to fall apart when it hits a bump.”

Teens, children and “even babies in utero whose nervous systems are still developing” are exposed to these toxins every day, Thiagarajan said. This “could explain why younger generations are doing progressively worse mentally as exposure grows across the planet.”

The authors combined the findings of over 400 studies to create a “narrative review,” which shows that neurotoxic and neurodisruptive chemicals in pesticides, heavy metals, ultraprocessed foods and plastic food packaging harm brain development and mental function in young people.

Ultraprocessed foods can contain “thousands of unregulated chemicals” that avoid regulatory scrutiny under the catch-all phrase of “natural flavors,” Thiagarajan said.

Heavy metals seep into people’s water supply and food. Pesticides are sprayed on grains and produce. Many foods and drinks are packaged in plastic that leeches endocrine-disrupting chemicals.

Studies show chemicals from these sources kill or degrade brain cells, or block how brain cells communicate, said Thiagarajan.

Young people’s exposure to these toxins “poses an immediate and pervasive public health issue that is an existential threat to the very fabric of human society,” the authors wrote in their report, published July 18.

Toxins in food, water ‘largely ignored’ by neuroscience researchers 

The report traces how children and teens worldwide generally feel more hopeless and anxious compared with young people in their grandparents’ generation.

This shift has occurred while the food and water consumed by young people and pregnant women have become more polluted with chemicals from pesticides, ultraprocessed foods, heavy metals and plastic food packaging, the review states.

Older people are also exposed to the toxins, but children and teens are more vulnerable, according to the authors. They wrote:

“Children are fundamentally more vulnerable to toxic and disruptive chemicals due to their immature metabolic pathways, the rapid maturation and plasticity of their developing brain, and their lower body weight.”

The impact of toxic chemicals on young people’s mental health is “largely ignored” by the neuroscience and neuroimaging community, the authors wrote.

“Much of the mental health discourse has been about stress, adversity and smartphones, with therapy as the primary solution,” Thiagarajan said.

Over the last decade, journals outside the neuroscience community have published an increasing number of studies on pesticides, ultraprocessed foods, microplastics, endocrine disruptors, heavy metals, food additives and bisphenol A.

However, few studies on those topics are printed in top-ranking neuroscience, neuroimaging and psychiatry journals, according to the report.

Strong science needed to spur regulatory action

Regulatory action is needed to reduce children’s and pregnant women’s exposure to these toxins, but high-quality studies are needed to spur that regulatory action, the authors said.

Regulators have dismissed previous research on neurotoxins as methodologically weak or inconsistent because of small sample sizes or a lack of standardization.

But the authors say there is an “urgent need for more funding and research to understand the risks to the developing brain so that effective regulations can be put in place.”

Funding for research must prioritize “large-scale, transdisciplinary research initiatives that engage neuroscientists, mental health professionals, environmental toxicologists, nutritional scientists, and policymakers,” according to the review.

The authors said their report covered only toxins from food and drinks, not other sources such as personal care products, clothes, toys or air pollution.