I meant to write about a recent finding linking proximity to freeways with autism nearly a month ago. But then Sophie started night waking again and resisting naps, which left me tired and strapped for time. She is sleeping peacefully at the moment, so, with a cup of green tea by my side, I’m excited to share my thoughts on this not-so-surprising relationship between environmental toxicities and autism.

This study examined the potential link between air pollution exposure during pregnancy and autism incidents in children.  Researchers compared prenatal and perinatal distance from homes to freeways among 304 preschool children with autism and 259 children without autism. They found that mothers who lived near a freeway (<309 meters) were more likely to have children with autism.  This association was not present among mothers living near other types of roads.

This finding is significant and further supports the link between environmental toxicities and increased rates of autism. Air pollutants such as nitrogen dioxide, carbon monoxide, sulfur dioxide, and ambient particulate matter cause oxidative stress and inflammation, especially in those with a genetic predisposition that prevents efficient metabolization of those compounds.  Oxidative stress represents an imbalance between pro-oxidants and anti-oxidants, resulting in cellular damage by reactive oxygen species (ROS). ROS are natural byproducts of metabolization and, if not neutralized by anti-oxidants such as vitamins A, C, E and glutathione, can build up in the body and contribute to the development of neuropsychiatric disorders, such as autism.

The relationship between genes and patterns of health and disease is dependent upon environmental exposure and our inherent levels of nutrients and phytochemicals.  As more research continues to support the gene-environment connection, the medical community needs to emphasize prevention as well as finding cures. Prevention includes cleaning up the environment, optimizing diet and vitamin/mineral intake, and even screening children who may have a genetic predisposition towards oxidative stress. This means an individualized vitamin and mineral supplementation plan that can protect against autism and other neuropsychiatric disorders.