Hair graying is primarily caused by a decrease in follicular melanocyte stem cells (MSCs) or their dysfunction, according to a June 2025 review published in Clinical, Cosmetic and Investigational Dermatology. While often viewed as a simple sign of aging, new research indicates that hair pigmentation is a complex biological process influenced by genetics, environmental factors, and lifestyle.
Why does hair turn gray as we age?
Hair graying occurs when the cells responsible for hair color lose their pigment, according to the Cleveland Clinic. As individuals age, hair follicles produce strands that are gray, white, or silver rather than their original color. While many people notice these changes in their 30s or 40s, the timeline for graying varies significantly; some individuals may see their first gray hairs in their 20s, while others may not experience a full head of gray hair until their 50s or 60s.
Hair doesn’t actually “turn” gray. Once a hair follicle produces a strand, the color is set. Graying is the result of the follicle no longer producing pigment for new hair growth, according to Harvard Health.
Can stress really cause gray hair?
Scientific evidence confirms that psychological stress can accelerate the graying process. A study published on June 22, 2021, in the journal eLife provided the first quantitative evidence linking psychological stress to graying hair in humans. Senior author Martin Picard, PhD, an associate professor of behavioral medicine at Columbia University Vagelos College of Physicians and Surgeons, noted that the data suggests human aging is not a fixed biological process and may, in some cases, be temporarily reversed.
This finding contrasts with earlier studies in mice, which suggested that stress-induced graying was caused by an irreversible loss of stem cells. Researchers at Columbia University observed that when stress was eliminated, hair color was restored in some instances, highlighting the malleability of the aging process.
What are the primary causes beyond aging?
Beyond the natural aging process, several factors can contribute to the appearance of gray or white hair. According to the Cleveland Clinic, these include:
- Genetic conditions: Family history often determines the age at which graying begins.
- Vitamin deficiencies: Certain nutritional gaps can impact hair health.
- Medications: Specific pharmaceutical treatments may lead to pigment loss.
If you notice sudden or widespread graying at a young age, consult a primary care provider. It is important to rule out underlying medical conditions or nutritional deficiencies that could be addressed through clinical care.
Frequently Asked Questions
Does plucking a gray hair make more grow back?
No. Plucking a gray hair will not cause more to grow in its place. However, it can damage the hair follicle, which may eventually lead to hair thinning or scarring in that area.
Is it possible to reverse gray hair?
Research led by Columbia University suggests that in cases where graying is linked to stress, hair color may return once the stressor is removed. However, most graying associated with natural aging is currently considered permanent.
Do lifestyle choices impact how fast I go gray?
Yes. According to a June 2025 report in Clinical, Cosmetic and Investigational Dermatology, lifestyle and environmental factors play a significant role in the dysfunction of melanocyte stem cells, alongside genetic predispositions.
Have you noticed changes in your hair color during periods of high stress? Share your experiences in the comments below or subscribe to our newsletter for more insights into the science of aging and health.
