A trace mineral most people rarely think about—copper, needed only in tiny amounts—may hold a key to understanding why some people with autism struggle with social connection and have less nerve-insulating tissue in their brains. Researchers at Niigata University have uncovered a striking biological link: individuals with autism spectrum disorder who had lower copper levels in their blood also showed more severe autism symptoms and reduced white matter volume, the brain tissue that carries signals between different regions.
The finding matters because it shifts how scientists think about autism's origins. Rather than focusing solely on the brain itself, this research suggests that trace element imbalances in the body—measurable in blood—can cascade into changes in how the brain develops. White matter, largely made up of nerve fibers wrapped in myelin, is what allows information to travel efficiently through the brain. When myelin production suffers, brain communication suffers with it.
The Niigata team conducted a thorough investigation combining three approaches: they measured 21 different elements in blood plasma from people with autism and typically developing controls, scanned brains with MRI to measure white matter, and built mouse models to test cause and effect. Among all the elements tested, copper stood out clearly. Lower plasma copper levels correlated with higher clinical symptom scores for autism. The brain imaging showed the same people had reduced white matter volume, which in turn was associated with social symptoms specifically.
To understand the mechanism, the researchers created mice with developmental copper deficiency. These animals exhibited autism-relevant behavioral changes—altered social behavior and repetitive movements. In their brains, the copper deficiency reduced the number of oligodendrocytes, the specialized cells that produce myelin. The cells that did exist matured poorly, and myelin formation decreased overall.
The molecular detective work revealed an intricate chain of events. Copper deficiency disrupted a process called HIF1α-related regulation, which normally helps form blood vessels and manage metabolism in the developing brain. This triggered oxidative stress and mitochondrial dysfunction—the powerhouse structures in cells stopped working properly. The cell's quality-control system, called mitophagy, went into overdrive trying to remove damaged mitochondria. This hyperactive cleanup suppressed mTOR signaling, a crucial pathway for cell growth and oligodendrocyte development.
Here is where the research took a hopeful turn: when the team artificially activated mTOR signaling in the copper-deficient mice, oligodendrocyte maturation improved and social behavior improved. Yet the researchers emphasize caution. They explicitly state their findings do not support copper supplementation as an autism treatment. Autism itself is highly diverse, and copper levels vary across individuals. What matters is that the study provides a biological framework—a roadmap showing how trace element imbalance, mitochondrial health, and white matter development are interconnected during brain development.
The Niigata University work, published in Science Advances, opens a new frontier. Future research will test whether measuring individual trace element profiles alongside clinical assessments and brain imaging could identify biological subgroups within the broader autism diagnosis. This could eventually enable more precise understanding of neurodevelopmental conditions. The study also reminds scientists to look beyond neurons themselves, recognizing that metabolism and glial cells—the brain's supporting cast—shape brain function in profound ways.