Hair color can change over time for a variety of reasons. While some causes are natural, like aging, others may indicate an underlying health condition. Understanding why your hair color shifts can help you get to the root of any problems.
Hair color is determined by the amount and type of melanin pigments produced in hair follicles. As we age, the pigment cells that produce melanin slow down and eventually stop producing pigments altogether. This causes hair to turn grey and eventually white. But other factors can cause hair color to change prematurely, especially turning brown earlier than expected.
In this article, we’ll explore the leading causes of premature brown hair, including genetics, thyroid disorders, vitamin deficiencies, smoking, and sun exposure. We’ll also provide tips on how to slow or reverse brown hair for a more youthful look.
Genetic Causes
Genetics play a major role in determining hair color. Research shows that more than 100 genes influence hair color development. If you have ancestors from parts of the world where brown hair is common, like Southern Europe and Asia, you may be genetically predisposed to turning brown earlier.
Here are some of the key genetic factors that lead to premature brown hair:
- MC1R gene – Carries instructions for melanocortin 1 receptor protein. Variants increase brown eumelanin production.
- TYRP1 gene – Controls production of brown eumelanin.
- OCA2 gene – Helps determine brown vs. black eumelanin levels.
- SLC24A5 gene – Reduces production of brown melanin.
While you can’t change your genetic makeup, understanding your hereditary risks can help you proactively slow changes to brown hair.
Thyroid Disorders
The thyroid gland in your neck produces hormones that regulate cellular metabolism. When the thyroid is underactive (hypothyroidism) or overactive (hyperthyroidism), it can disrupt melanin production and trigger premature browning.
Here’s an overview of how the most common thyroid disorders impact hair color:
| Thyroid Disorder | Effect on Hair Color |
|---|---|
| Hypothyroidism | Slows cell turnover, leading to buildup of brown melanin |
| Hyperthyroidism | Accelerates cell turnover, depleting melanin reserves |
| Hashimoto’s disease | Chronic thyroid inflammation causes hair to brown |
| Graves’ disease | Antibodies attack thyroid, triggering melanin changes |
Getting your thyroid levels tested can help diagnose any underlying issues. With treatment, thyroid disorders may reverse some of the hair color changes.
Vitamin Deficiencies
Lacking key vitamins can impact melanin production and cause hair to turn brown prematurely. Here are some of the main vitamin deficiencies linked to brown hair:
- Vitamin B12 – Needed for melanin synthesis. Deficiency causes buildup of brown melanin.
- Biotin – Plays a key role in keratin infrastructure for hair growth. Lack of biotin causes hair to brown and thin.
- Copper – Trace mineral that aids melanin production. Low copper speeds up graying and browning.
Getting enough of these essential vitamins can help support your body’s melanin production and keep hair in its natural color longer. Work with your healthcare provider to test your levels and supplement if needed.
Smoking
Smoking has been linked to premature graying and browning of hair. Chemicals in cigarette smoke generate free radicals that damage melanin pigment cells. This speeds up depletion of color pigments.
Studies show smoking 10 or more cigarettes daily doubles your risk of graying before age 30. The oxidative stress on hair follicles also causes premature transition to brown shades.
Quitting smoking and avoiding secondhand smoke can help halt further pigment loss. But any hair color changes that have already occurred are irreversible.
Sun Exposure
Exposure to UV radiation from the sun speeds up oxidative damage to melanin-producing cells. This causes hair color to fade at a faster rate. While graying is more common, sun can also trigger premature browning.
Here’s an overview of how sun impacts hair pigment:
| UV Effect | Result |
|---|---|
| Destroys melanocytes | Stops melanin production |
| Fades existing melanin | Hair lightens and turns brown |
| Oxidative stress | Depletes pigment reserves |
Wearing sunscreen, hats, and avoiding excessive sun exposure can help minimize UV damage to your hair.
How to Reverse Brown Hair
While genetic causes of premature brown hair can’t be reversed, you may be able to slow or cover up some of the color changes with the following strategies:
- Balance thyroid hormones – Getting thyroid disorders like hypothyroidism under control can help normalize melanin production.
- Correct vitamin deficiencies – Supplement with vitamins B12, biotin, and copper to support melanin synthesis.
- Quit smoking – Giving up smoking curtails oxidative damage to hair pigment cells.
- Use sun protection – Shield hair from UV rays to minimize fading of melanin.
- Dye hair – Cover up brown hues with color-restoring products or dyes.
- Try melanin boosters – Opt for shampoos and treatments with melanin-stimulating ingredients.
While you can’t change your genetics, managing health conditions, improving diet, and protecting your hair can help slow premature browning as you age.
The Takeaway
Premature brown hair can be distressing but is rarely cause for concern. Understanding the common reasons hair color changes to brown allows you to address any underlying issues.
Genetics play a major role, but thyroid problems, vitamin deficiencies, smoking, and sun exposure can also lead to premature browning. Getting to the root of any medical issues and improving hair care makes a difference.
While some discoloration is inevitable over time, proactive steps like dietary changes, supplements, and melanin-boosting products can help keep your hair looking its vibrant best for longer.