Causes of Gray Hair

by Vanya Sharma last updated -

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The majority of people consider gray hair as an indication of old age setting in. However, if you have gray hair at an early age, remember it is not the body that defines the age, it is the mindset.

Normally, it is seen that hair begins to gray on the head, then on the face and slowly progresses to other places like the chest and the armpits. This process of graying begins at an average age of 35 years or more and the graying progresses gradually over the years. In some people, the age at which graying starts can differ. For some, graying might begin at an early age and for some, it might begin after 40.

The difference in the age of graying is dependent on genetics and other factors. Before we understand why hair turns gray, it is important to know about the structure of hair to fully grasp the mechanism behind the graying of hair.

Hair is a biomaterial composed of a protein called keratin. Hair grows in follicles in the dermis layer of skin. Hair color in humans is found in the hair follicles because of the presence of two types of melanin, namely eumelanin and pheomelanin. Generally, more the melanin, darker the hair color.

What Causes Gray Hair?

The dilution of eumelanin and pheomelanin pigments result in graying of hair. To be precise, the melanocytes inside the hair follicles stop producing melanin and this results in graying of hair. Recent research has shown that a decrease in melanin is due to the decrease of an enzyme in the body called catalase. Catalase breaks down hydrogen peroxide buildup in the body. When there is a reduction in the count of catalase, hydrogen peroxide suppresses the growth of melanin, resulting in the graying of hair.

A significant amount of gray hair can appear in younger people too. This phenomenon is called premature graying. Some of the known causes of graying of hair include:

Genetic Graying

Sometimes, genetics do have a role to play in premature graying of hair. Premature graying can be seen in children as young as 12. In some cases, the hair might gray for some time and then turn back into black or natural color as the year’s pass. However, in most cases, graying of hair continues.

Vitamin B12 Deficiency

A vitamin B12 deficiency can also be responsible for the graying of your hair. This happens when your body is unable to absorb ample quantities of vitamin B12 nutrient as a result of pernicious anemia. This condition leads to early and faster graying of hair.



Research shows that those who smoke have a very higher chance of experiencing graying of hair in their early 30’s than those who don’t smoke. This is attributed to the release of free radicals in the body caused by smoking. Free radicals cause oxidative stress, which in turn reduces the pigmentation capacity of melanin and directly lead to graying of hair.


This is another factor that leads to oxidative stress, thereby causing graying of hair.

Hydrogen Peroxide

Hydrogen peroxide is the chemical used in bleaching. It is also naturally produced by our body. When this starts interfering with melanin (pigments that give color to skin and hair), the hair turns gray.

Emotional Stress

Emotional stress can lead to premature graying of the hair. Research studies have shown that the release of adrenaline for a sustained period of time had a damaging effect on the DNA, causing it to develop abnormalities. This is also believed to play a major role in graying of hair.


Premature graying is seen in the presence of certain diseases related to the thyroid gland such as Grave’s disease, Hashimoto’s disease, hyperthyroidism, hypothyroidism, anemic conditions, and can also appear in skin areas affected by leucoderma. Some people with the condition of vitiligo, where irregular white patches form on the skin have been known to develop early gray hair.

Improper Diet

An improper diet can also be attributed to premature graying of hair. Lack of vitamin-12, iron, and iodine are considered to be the causes for early graying of hair. Lack of healthy protein intake is also attributed to early graying of hair. Excessive tea & coffee consumption and smoking may also contribute to early graying.

Hair Dyes & Hot Water

Use of chemical hair dyes and extremely hot water for hair are also considered to cause early graying of hair.


Every decade after the age of 30, the chances of graying hair stand at 10 to 20%. Protection Status
About the Author

Vanya Sharma handles the medical expert collaboration for Organic Facts. A writer at heart, she joined the website while she was still pursuing her English Literature degree from IGNOU, Delhi, India. She is also responsible for the website’s monthly newsletter and website content and contributes to Facebook, Instagram, and YouTube regularly. Currently pursuing an e-course offered by Stanford University, ‘Introduction to Food and Health’, she aims to bring unbiased and helpful information to all those seeking to make their health and lifestyle a priority.  

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