What Causes Grey Hair – Surprising Reasons You Didn’t Know - hair buddha
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What Causes Grey Hair – Surprising Reasons You Didn’t Know


One day we are all going to get white hair and wrinkled skin.

But if this happens too early then it needs attention.

I have seen my dad’s side of family stay/look young for a long time. My dad is 65 years of age and his 70 to 75 percent hair is still black. Most people will put it down to the genes. Yes could be. But I must also tell you that my dad’s side of family are all health freaks. They have to eat so many fruits, vegetables, and nuts in a day.

I do believe that early greying and for that matter signs of old age can be pushed aside by leading a healthy lifestyle.

But it’s not all straightforward.

My DadPeople start going gray at different ages and to different degrees – it may occur slowly over many decades or rapidly in life. Although, it is said that Caucasians go grey first, then followed by Asians and lastly Africans.

Going grey can also mean that you have a hidden medical problem.

When I was researching on vitamin B12 deficiency, a lot of people on forums said that their grey hair turned back to original colour after supplementing with vitamin B12.

That is so unfair on people who go undiagnosed for years and turn grey; plus you suffer too many ill-effects of the B12 deficiency such as depression and brain fog.

But it’s not just B12, there are many more reasons that can turn you grey at a young age.

Poor lifestyle is a big one. Also, if you have an underlying medical condition such as low thyroid, or have a deficiency of certain vitamins and minerals, or experienced a stressful event (such as a death in the family or divorce) then you are more likely to go grey early.

The good news is that it may be possible to reverse grey hair if you were to get rid of the causative factor. But first, let’s understand how this happens…

What gives hair its colour?

Hair colour is very fascinating.

Hair follicleThe answer lies in the pigment called melanin. The root of your hair is located below the scalp and is seated in a tube like structure called as the hair follicle. And within these hair follicles lie melanocytes which produce pigment granules – melanin. When the hair is still inside the follicle, melanin is injected into the growing hair fibres, and gives hair its colour.

melanocytes = melanin (colour) producing cells

melanin = natural hair dye

Melanin is of two different types: Eu-melanin – which contains brown and black colour pigments, and Pheo-melanin – which contains red and yellow colour pigments.

These combine in various proportions to give a beautiful range of shades – black, brown, blonde, red, et al.

Your hair colour will depend on your genes; which will determine the amount and combination of these colour pigments.

What Causes White Hair: Hydrogen peroxide & Free Radicals

What causes grey hair

Earlier it was thought that hair turns grey merely due to the loss of the pigment-forming melanocytes.

But new research says something else….

Greying of hair is caused due to increased levels of hydrogen peroxide (H2O2), which literally bleaches the hair from the inside out.

At any age, our body cells, as well as our hair cells produce H2O2 as a by-product of regular metabolism.

But in young and healthy people, these H2O2 molecules are quickly broken down into harmless elements of oxygen and hydrogen.

But as we age, H2O2 is broken down less and builds up in large amounts in the hair follicle and ultimately stops the synthesis of the colour pigment melanin.

Besides, a high concentration of H2O2 and other free radicals in our body causes signs of ageing such as: wrinkles, arthritis, brain degeneration, heart disease, etc.

So the answer to staying youthful and delay greying lies in the quick removal of these free radicals.

Note: Hydrogen peroxide is not a free radical itself, but easily converts to free radicals like OH, which then do the damage.

How Does our Body Gets rid of Excess Hydrogen Peroxide?


Our body is pretty incredible. It has an answer for every problem. To counteract the effect of hydrogen peroxide (H2O2) it produces various antioxidant enzymes such as: Catalase, MSR and Glutathione peroxidise.

Also, the antioxidant vitamins that we eat – vitamin C, E, and A, protect our bodies (including our hair) from the damaging effects of free radicals.

In a recent study, researchers found that people with grey hair had a massive concentration of H2O2 in their hair; plus they had low levels of enzyme catalase and MSR. Just the opposite, people with dark hair contained significantly higher levels of catalase and MSR. And they also had very minimal H2O2 in their hair.

So these antioxidant enzymes play a vital role in preserving our hair colour. Let’s see each of them:


Catalase is your first line of defence in protecting the hair follicles from harmful effects of H2O2. It quickly breaks down H2O2 to water and oxygen. Apparently, one molecule of catalase can convert approximately six million molecules of hydrogen peroxide to water and oxygen each minute. So this enzyme is very potent.

But as we age, our bodies produce less catalase. Even factors such as stress and poor nutrition can cause catalase levels to go down. This causes the build-up of hydrogen peroxide in the hair follicles – which breaks down the hair pigments, as a result the hair turns white.

Catalase also protects our body cells from the damage of H2O2. Catalase deficiency has been implicated in age-related diseases such as cardiovascular disease, diabetes, and other chronic conditions.

Foods that contain Enzyme Catalase

The good news is that several foods contain high levels of enzyme catalase. And eating them regularly will help return your natural hair colour back. Catalase rich foods include: almond, wheat grass, garlic, onion, leeks, cabbage, broccoli, kale, cucumber, collard, turnip greens, carrots, radish, cherry, potatoes, and sweet potato.


This is another important enzyme which helps to preserve our hair colour. It doesn’t act directly on H2O2 but works to repair the damage caused by the peroxide. MSR stands for methionine sulfoxide reductase, and A & B are its two variants.

The presence of H2O2 creates hydroxyl radicals (free radicals) that break tyrosinase down.

Tyrosinase is the key enzyme needed for melanocytes to produce the pigment melanin. (Tyrosinase activates the production of melanin and other pigments from one type of amino acid – tyrosine by oxidation, as in the blackening of a peeled or sliced potato exposed to air. – from Wikipedia)

Thus, the breakdown of tyrosinase hampers the synthesis of colour pigments.

But to the rescue comes the enzyme MSR. It can fix the damaged tyrosinase so that it can carry on with colour production.

Sadly, with advancing age, the production of MSR too declines and they can’t do as much damage control.

Glutathione peroxidase

This enzyme also plays a decent role in reversing grey hair. Although not as potent as catalase, it works similar to catalase and converts H2O2 into water. So increasing glutathione peroxidase may be another way to decrease hydrogen peroxide.

The Role of Lifestyle and Diet in Hair Whitening


Smoking Causes Hair Greying

Did you know that 1 billion people smoke on this planet? I was stunned at this statics, didn’t know the number was so high.

Smoking has long been linked to premature ageing of the skin and is now associated with greying hair as well as hair loss. A study published in Indian dermatology found that smokers are 2.5 times more likely to begin graying prematurely compared to non-smokers.

One reason is that smoking generates more H2O2 and other free radicals. And we saw above how these free radicals hamper the colour-producing cells – the melanocytes. Thus resulting in whitening of hair.

2. Stress


Taking stress doesn’t change the situation; in fact, it makes it worse. Stress is exhausting for your body as well as your mind. And stress also exhausts the supply of enzyme catalase.

Besides, stress also increases the production of free radicals, which then disrupts the activity of melanocytes. So it’s a double whammy.

Remember this:

Stress ⇒ low catalase + excess free radical ⇒ aging

So don’t stress out, just stay calm and face the problem 🙂

 3. Alcohol

Excess alcohol decreases the enzyme catalase. Plus, drinking too much alcohol can take a serious toll on your health.

So cut down on your drinking. But sometimes giving up completely is a good idea.

4. Junk food


I was talking to a nutritionist a few months ago and she said that potato chips or fries, in particular, are the worst of all junk foods; as they generate tons of free radicals.

And when free radicals outnumber the antioxidant defences (from healthy diet and body enzymes) it will dramatically speed up ageing.

So if you desire healthy body, glowing skin and beautiful hair, avoid Junk food as much as possible. And eat real foods that are grown on plants and not made in plants.

5. Pollution


You are constantly exposed to pollution from – air, water and harmful chemicals. It is difficult to avoid air pollution, but you can take measures to minimise water and chemical pollution. Harmful chemicals from laundry detergent, soap, shampoo, room freshener, and floor and toilet cleaners can build-in your system and in turn produce more free radicals.

Use natural alternatives for shampoo, soap, detergents, and air freshener. Also, if possible drink filtered water. And keep plants such as aloe vera, bamboo and palm in your house as they purify the air and make it cleaner.

6. Lack of Minerals – copper, iron, manganese, and selenium


Minerals such as iron, copper, manganese and selenium work along with antioxidant enzymes to remove the free radicals.

  • Iron and manganese are needed for activity of catalase.
  • Selenium helps the glutathione peroxidise to break down hydrogen peroxide
  • Copper is essential to enzyme tyrosinase, which is the key enzyme in colouring the hair.
  • Iodine is needed for the production of thyroid hormones T3 & T4 – which affect the functioning of melanocytes.

7. Lack of antioxidant vitamin – A, C & ELack of antioxidants cause grey hair

Lack of antioxidants cause grey hairThese antioxidant vitamins work similar to catalase by breaking down and removing free radicals.

For example, vitamin C readily reacts with hydrogen peroxide before it can initiate any damage, and converts it into safer elements: water and dehydroascorbic acid.

Medical Conditions that can Cause Grey Hair

1. Thyroid — Hypo or Hyper

Cause of grey hair: thyroid hormones

Cause of grey hair: thyroid hormonesThe thyroid gland is a butterfly-shaped organ located at the base of your neck. It releases hormones T3 and T4 which influence the metabolism of your body cells – meaning it regulates the speed with which your body cells work.

When the thyroid is underperforming (hypothyroid), less T3 and T4 will be produced — this can considerably affect the synthesis of hair colour. The opposite is also true; a hyperthyroid condition will produce excess amounts of T3 and T4, but it will also lead to an increase in autolysis (self-digestion) of catalase, thereby decreasing catalase levels in the body over time.

But once you correct the hormone levels there are fair chances that darkening of white hair may occur in some people.

2. Vitamin B12 deficiency 

Cause of Grey Hair: Vitamin B12

Vitamin B12 is essential in keeping colour in your hair.

B12 is needed for DNA synthesis, which governs the functioning of body’s cells. So when the B12 levels are low (or for that matter any vitamin levels are low), the hair cells will be cut off first as they are not necessary for our survival. This can, in turn, affect the activity of melanocytes, causing the hair to lose its pigment and turn white.

Besides, when there is a lack of B12, homocysteine levels rise.

Elevated homocysteine has been suggested to directly generate H2O2.

B12 can help reduce the levels of homocysteine by converting it into amino acid methionine. (A high level of homocysteine is also a risk factor for heart disease).

The deficiency of B12 is more common in vegans or vegetarians, as b12 is mostly found in animal products such as dairy, eggs, chicken, meat and fish. Other signs of B12 deficiency are shortness of breath, fatigue, memory problems, and confusion. So check your B12 levels if you are unsure.

The good news is once you correct b12 deficiency your hair will return to its original colour again.

More on vitamin B12 and how to correct the deficiency here.

3. Low levels of Vitamin D

There could be a link between greying and low bone density. One study found that levels of vitamin D3 were either deficient or insufficient in all the participants with premature grey hair, indicating an important role in pigmentation of the hair.

 4. Vitiligo

Vitiligo occurs due to a lack of melanin in the affected areas of skin. It’s not clear exactly what causes this lack of melanin, but it has been linked to problems with the immune system (autoimmune conditions).

Other medical conditions that cause premature greying include: albinism and Werner syndrome

True or False?

I have heard many people say that once you start dyeing your hair, all your hair will turn grey soon.

Is it true? Not sure. (what do you think?)Again, hydrogen peroxide may have a role to play in this too, as many of the hair dyes contain hydrogen peroxide as an oxidising ingredients.

If you have experience this or come across similar finding, do share in the comment box below.


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Leave a Comment:

Princess says

Awesome and well detailed information. Thanks so much ma.

Megha says

Hi.. I m just 26 yr.. And my 60% hair got grey.. Can they be reversed in natural colour.. I have tried many remedies.. But there is no effect.. And also a huge hair fall

Sunshine Boppi says

Hi Minaz, thanks for a wonderful post. I have been having chronic sinus and my hair is 40% grey and I am 38 year old. I eat food thats only hot and avoid all cold causing ones.
I have one question, if I have sinus does that not mean, I have excess cold in body thats why I should be eating only hot foods? YOu think even though I have sinus, my body can be called pitta body?

    Minaz @hairbuddha says

    Hi, you could be a combination of two dosha: pitta and kapha. You can check it online for free (search dosha quiz) or go to ayurvedic doctor.
    In cold weather eat heating foods and in summer eat cooling foods (avoid fridge water and drinks).

parminder kaur says

Hello mam,

40% of my hair are gray and my age is just 25 years.

I rinse my hair with a mixture of Bhringraj, amla, Sikakai, Reetha and neem prepared by leaving it overnight then boiling it the next day.

Also, I’m eating 1 spoonful amla powder by Patanjali everyday on Empty Stomach.

How long will it take to turn my hair into black again? .. The hair will come black from the roots itself??

    Minaz @hairbuddha says

    Hi Parminder, that is superb. It will take 6 to 8 months.
    Also include fresh amla, if you can, and coconut and ghee in your diet.

Sremedies Tips says

Hi.Now a days I’m hearing about indigo leaves powder for reversing grey hair.will it work for this problem? how to use it?

    Minaz @hairbuddha says

    Indigo powder is a natural dye. You always use it with henna. Check this post on how to use it.

Prashant Agarwal says

Have you tried egg oil for reversal of grey hair?

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Sitankp says

Hi Minaz,
I have lots of grey hair and I’m coloring for the past few years.
Because of hair loss I’m planning to switch to the natural method. But,heard that we should not use henna on colored hair. Can you please suggest few alternative? I last colored my hair two weeks back, so if I have to use henna then how long I have to wait?

Thank you

    Minaz @hairbuddha says

    Hi Sitankp,
    As far as I know you can apply henna on hair dye.
    Do add amla/beet root/ fenugreek seed powder in your henna, it will enhance your colour.
    Let us know how it goes.

      Sitankp says

      Thank you so much!
      Can you please tell me the ingredients and their proportion to add along with henna powder? My hair is very dry, so will oiling before henna reduce its color ?

      Minaz @hairbuddha says

      I will be doing a post on henna soon.

      Sitankp says

      Thank you so much

Dishy says

Well done Minaz; great job. This is very informative, I truly appreciate you. I’ve learnt a whole lot of good stuff which I’m going back work with.
Keep doing what you do best ??

Debbie says

Very well researched and detailed post. It certainly gives me pointers to where I should look for correcting my graying hair. Thanks for taking the time for researching and sharing.

    Minaz @hairbuddha says

    Thanks Debbie, glad you found it useful.

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