Simple Non-Invasive Hair-Based Test Could Speed ALS Diagnosis

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease that often takes more than a year to diagnose after symptoms appear. Early detection is critical, as it can improve quality of life and potentially prolong survival, but current biomarkers are invasive, expensive, and difficult to integrate into routine care. Researchers have now shown that a single strand of hair can reveal unique elemental patterns that distinguish ALS patients from healthy individuals. This paves the way for a simple, non-invasive hair-based test to speed ALS diagnosis and improve patient care.

In a study led by the Icahn School of Medicine at Mount Sinai (New York City, NY, USA), researchers used advanced laser ablation-inductively coupled plasma-mass spectrometry to analyze single hair strands. This technique vaporizes tiny particles to measure elemental and isotopic composition, providing up to 800 time points of data per strand at two- to four-hour intervals. The investigators assessed 17 elements, including copper, zinc, magnesium, and lead, and applied information-theory tools to map how patterns shifted over time.

Image: Hair samples were collected from ALS-positive cases and ALS-negative controls (Photo courtesy of Mount Sinai Health System)

The analysis included 391 people, 295 with ALS and 96 healthy controls, with hair samples collected from both a regional ALS center and nationwide. Results showed patients with ALS had significantly lower synchrony in copper-based elemental networks, suggesting systemic dysregulation in copper metabolism. The findings, published in eBioMedicine, revealed sex-specific differences, with men showing weaker copper-zinc dynamics and women showing disruptions in chromium-nickel patterns.

The study provides proof-of-concept that hair could serve as a non-invasive, scalable biomarker for ALS. A hair-based test might help shorten the time to diagnosis, enabling patients to access medications, nutritional plans, therapy, and assistive devices earlier. Researchers stress that while not yet a diagnostic test, the approach could transform care by making ALS detection faster, easier, and more accessible, with future work needed to refine and validate its use in clinical practice.

“Our study demonstrates that hair can serve as a window into the body’s elemental balance,” said Manish Arora, BDS, MPH, PhD, 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, non-invasive way. This approach has the potential to transform how we diagnose ALS, making it faster, easier, and more accessible for patients.”

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