Researchers at the Icahn School of Medicine at Mount Sinai have shown for the first time that a single strand of hair can reveal unique elemental patterns that distinguish people with amyotrophic lateral sclerosis (ALS) from healthy individuals. The findings, published in eBioMedicine, suggest that a simple, noninvasive hair-based test could one day speed up ALS diagnosis and improve patient care.

ALS is a progressive and fatal neurodegenerative disease, typically taking 10 to 16 months from symptom onset to diagnosis in the United States. Earlier detection is critical since it improves the patient’s quality of life and therefore potentially prolongs survival, but current fluid- and imaging-based biomarkers are often invasive, expensive, and difficult to integrate into routine clinical care. According to the ALS Association, the average survival time is three years, though about 20% of people with ALS live five years, 10% survive 10 years, and 5% live 20 years or longer.

Using advanced laser ablation-inductively coupled plasma-mass spectrometry, a technique that analyzes the elemental and isotopic composition of solid samples by using a laser to vaporize tiny particles, the research team analyzed single hair strands from 391 people (295 ALS-positive cases and 96 controls). Each hair strand provided up to 800 time points of data, representing elemental fluctuations at approximately two to four-hour intervals.

The investigators measured 17 elements—including copper, zinc, magnesium, and lead—and used sophisticated information-theory tools to assess how elemental patterns shifted over time.

The study adds to evidence that copper plays a central role in ALS. Patients with ALS showed significantly lower synchrony (less coordinated, less similar, and less aligned in time) in copper-based elemental networks compared with controls, suggesting systemic dysregulation in copper metabolism. Male patients demonstrated weaker copper-zinc dynamics, while female patients showed disruptions in chromium-nickel patterns.

“Our study demonstrates that hair can serve as a window into the body’s elemental balance,” said Manish Arora, BDS, MPH, Ph.D., the Edith J. Baerwald Professor and Vice Chair of the Department of Environmental Medicine at the Icahn School of Medicine at Mount Sinai, and senior author of the study.

“By analyzing the biodynamics of elements such as copper over time, we can detect disruptions associated with ALS in a simple, noninvasive way. This approach has the potential to transform how we diagnose ALS, making it faster, easier, and more accessible for patients.”

“This is the first-ever study to use hair strands to identify elemental dysregulation in ALS,” said Vishal Midya, Ph.D., Assistant Professor of Environmental Medicine at the Icahn School of Medicine and senior author of the study. “We found that patients with ALS had measurable differences in copper biodynamics that were not present in controls. These findings provide proof-of-concept that hair could serve as a simple and scalable diagnostic tool.”

While the study does not yet provide a diagnostic test, it shows that hair could be a promising new biomarker for ALS. A simple hair-based test might help shorten the time to diagnosis, allowing patients to start treatment and support sooner. Earlier care, including medications, nutrition plans, assistive devices, therapy, and counseling, can improve quality of life and may even extend survival.