Problems with Metabolizing Metals in Childhood Linked to Developing ALS in Adulthood

Adults who develop Lou Gehrig's disease (ALS) may have had problems metabolizing certain metals in childhood, according to scientists who studied the teeth of patients with the degenerative disorder.

The symptoms of the condition usually first show when a person is in their fifties or sixties. It's characterized by the death of nerve cells, causing patients to lose their ability to move. Eventually, it leads to paralysis. The cause of most cases is unknown, but there are thought to be hereditary and environmental factors at play.

To explore a potential link between certain metals and the disease, the authors of the paper, published in the journal Annals of Clinical and Translational Neurology, examined the teeth of ALS patients and 31 people without the condition who were the control group. They studied teeth from autopsies or dental extractions, with permission. Lasers were used to measure levels of essential nutrients and toxic metals in teeth markings that are comparable to the growth rings on trees. This enabled the scientists to chart each person's uptake of metals in childhood.

Levels of metals including chromium, nickel, tin, and zinc were higher in the teeth of ALS patients versus the controls. A similar analysis in mice with a condition similar to ALS verified their findings. In the mice, the team also found differences in the distribution of metals in the brain, suggesting a link between these substances and ALS.

Co-author Manish Arora, professor of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai, told Newsweek: "This study shows that metal dysregulation during specific periods in childhood and early adolescence is linked with the decades later onset of ALS."

Arora said: "Our team has been interested in the whole trajectory of brain health for over a decade. ALS is a very challenging disease to study because we don't know much about what causes it. Scientists have suspected that some environmental factors in early life are at play but so far the technology to identify those factors has not been available."

Christine Austin, assistant professor of environmental medicine and public health at the Icahn School of Medicine at Mount Sinai who co-authored the paper, told Newsweek teeth are "one of the only tissues in the body that archives information about early childhood and stores it for later analysis."

She said: "The most interesting finding is that biochemical pathways are disrupted as early as birth and childhood for a condition that manifests clinically in the 50s and 60s."

The study was limited as the sample size is small and participants came from the same study center Arora said, adding: "However, the similar results from the ALS mouse model is encouraging."

The team hopes the findings will lead to ways of predicting the risk of ALS in baby teeth after they fall out, Austin said. "This means there is potential to intervene and prevent disease onset, potentially through treatments of metal dysregulation."