The exact cause of autism is still unknown, but researchers have linked the condition to genetic and environmental factors, which includes zinc deficiency.
While it is not yet clear if zinc deficiency indeed contributes to autism, researchers of a new study published in Frontiers in Molecular Neuroscience defined a possible mechanism on how this could work.
Sally Kim, from Stanford University School of Medicine, and colleagues, demonstrated that zinc can shape the connections between brain cells that form during early development through a complex molecular machinery controlled by genes linked to autism.
Kim and colleagues found that when a brain signal is transferred via these connections known as synapses, zinc enters the target brain cells where it could bind the two proteins called SHANK2 and SHANK3 that cause changes in the composition and function of adjacent signal receptors known as AMPARs on the neuron's surface at the synapse.
Because zinc shapes the properties of developing synapses through SHANK proteins, a lack of the mineral during early development could contribute to autism by impairing the function of synapse that allows brain cells to communicate with one another.
"Given the zinc sensitivity of young neurons and its dependence on Shank2 and Shank3, genetic mutations and/or environmental insults during early development could impair synaptic maturation and circuit formation that underlie ASD etiology," the researchers wrote in their study, which was published on November 9.
It is important to note that the findings do not mean that doctors should start recommending taking zinc supplements to prevent autism.
"Currently there are no controlled studies of autism risk with zinc supplementation in pregnant women or babies, so the jury is still out," said study researcher Craig Garner, from the German Center for Neurodegenerative Diseases, according to Newsweek. "But experimental work in autism models also published in this Frontiers Research Topic holds promise."
Taking too much zinc can also have unwanted consequences on a person's health, such as the reduction of the amount of copper that the body absorbs. This can possibly lead to anemia and the weakening of the bones.
Zinc deficiency does not also necessarily mean there is dietary deficiency since it has other possible causes such as problems with absorption in the gut.
Autism is a developmental disability marked by significant social, communication, and behavioral challenges. People with autism may interact, communicate, behave, and learn differently compared with most people.
Figures from the U.S. Centers for Disease Control and Prevention show that about one in 59 children have autism spectrum disorder.