There comes a time when every curly girl will notice a silver strand or two among her coils.
Nowadays, hardly anyone panics at their first grey hair. But if you think your hair colour changed on you too soon, hair dye isn't your only resort.
You can stop or even reverse premature grey hair, here's how. . .
How early is too early to get grey hair?
Hair greying can happen at any age; some people reach their seventies before they find their first grey hair and a tiny number of people are born with some white hairs. That said, there is a medical threshold for what's called 'premature canities'. And it's a lot younger than most people might think:
If you're of African descent, and you get your first grey any time before your thirtieth birthday, that's considered premature hair greying. For Asians, that threshold drops to 25 and for Europeans it's just 20.
Hair greying is still one of the most mysterious parts of the ageing process, but scientists are piecing together just how our hairs start to turn grey.
Grey hair is not unusual on young people. Image by Nic Owuor.
They've figured out some of the causes and have even found remedies that can turn the hair greying process around.
We'll get to those in a minute, but to really understand how they could help reverse your grey hair, you need to know what makes hair go grey in the first place.
What causes hair to turn grey?
Natural hair colour depends on the pigment known as melanin, which is manufactured in cells called melanocytes.
The process is known as melanogenesis, and is fuelled by an enzyme called tyrosinase. When hair starts to turn grey, a few things happen: tyrosinase activity slows down, the number of active melanocytes drops, and there are fewer healthy pigment granules inside them.
Like all other signs of ageing, hair greying been linked to free radicals.
Every cell in our body is under constant attack from these highly reactive molecules that damage our DNA, proteins and lipids. Our cells are programmed to fight back, but whenever there's an imbalance between the free radicals in our system and our bodies' ability to detoxify them, the result is oxidative stress.
Premature grey hair has been linked to oxidative stress. Image by Natasha Brazil.
Over time, just from being on the planet, our cells experience more and more oxidative stress and accumulate free radical damage. This is what causes us to age.
Hair follicles are especially susceptible to free radical damage. The hair-making process that goes on inside the follicle generates a lot of its own oxidative stress.
Researchers studying grey hair follicles found they had very high oxidative stress levels and strong evidence of apoptosis - cell death - of the melanocytes which givesour its hair colour.
What causes premature greying?
The oxidative stress generated by our own hair cells over time eventually causes grey hair in most people, but what about those of us who get our first greys at a really young age?
Scientists think that this could be linked to increased oxidative stress from intrinsic factors like our genetics, plus extrinsic factors from our environment and lifestyle. Here's the shortlist of suspects:
Top 9 nutrients that prevent or reverse grey hair
AKA folate, this B vitamin is often used to increase hair growth, and plays a big role in hair colour, too. When it's not busy stimulating the rebuilding of hair follicle cells and stopping hair from falling out, folate finds time to stop your strands turning grey, too.
To get the benefits, make sure you're getting enough folate in your diet: kale, beets, green peas, brussel sprouts and kohlrabi all contain it, as do halibut, eggs and poultry.
Brussel sprouts are a good source of folic acid which protects against premature greys. Image by Mae Mu.
Yet another member of the B-vitamin family, this multitalented micronutrient goes to work overtime for your hair.
Taking care of growth, moisture and calming inflammation are just some of its duties at a scalp level. B5 is involved in melanin production too, one reason why it helps prevent hair from turning grey. And B5 actually goes a step further than folate: not only does it prevent grey, it can restore your natural hair colour, too.
You can find Vitamin B5 in whole grains, beans, mushrooms, eggs, cauliflowers and leafy greens.
We don't hear much about this mineral, but it has an important role to play in keeping hair from going grey before its time.
Like the B vitamins above, copper also helps in hair growth and strength, and when our levels run low, brittle hair that goes grey easily can be the result.
You can get your daily dose of copper in leafy greens, poultry or fish, as well as pistachios, dried apricots and figs.
This mineral is crucial for healthy hair, period. Many women are low on iron due to the blood loss that happens in menstruation, making iron deficiency the most common deficiency in the world.
Low iron can wreak havoc on your hair, causing everything from slow growth to thinning, hair loss and premature greying.
To keep your iron levels up, make sure foods like spinach, eggs, peaches, kale and red peppers are on regular rotation on your kitchen table.
Kale is a good source of iron which can prevent premature grey hair. Image by Deryn Macey.
As well as being a key mineral in our bones, calcium is also an important part of our hair. A study which looked at premature grey hair in Egypt found a negative correlation between calcium and iron levels and grey hair in the group of under 30s examined.
Supplementation with calcium (along with iron and copper) slowed and reversed the progression of premature grey hair.
Calcium is found in kale, parsley, fish, dairy products, walnuts and cabbage.
Zinc is another mineral that influences the whole hair building process. When the diet is low in zinc, hair growth slows down, and shedding, thinning, brittleness and pigment loss start to occur. You can stop all that by getting your zinc in fish, meat or pumpkin seeds.
The importance of Vitamin D, for everything from your bones to your brain, kidneys, immune system and beyond is regularly highlighted in the media.
What's less known is Vitamin D's impact on our hair. Vitamin D kickstarts the growth phase of the hair cycle, and is often found to be low in people with alopecia. Deficiency in Vitamin D is also linked to premature grey hair.
Your body will manufacture enough Vitamin D if you get high levels of sunlight. Image by Wilson Vitorino.
If you get enough sunlight, your body will make its own vitamin D. But for people living in countries with less sunshine, that's not enough - especially if you have medium to dark skin, which protects from sunlight. Taking in Vitamin D from food or supplements is crucial to prevent deficiency.
Your best food sources for Vitamin D are: meat, poultry, dairy products, oily fish like mackerel or salmon, as well as eggs, mushrooms and yeast.
Vitamin B12 is essential for protein synthesis and red blood cells, and is thought by scientists to play a key role in the hair follicle.
A study in India on people with premature grey hair found that, compared with subjects without greys, those with grey hair were low in both vitamin B12 and folic acid.
Vitamin B12 is only naturally present in animal products like poultry, meat, fish, milk and eggs.
Eggs are a good source of vitamin B12 and methionine, both linked to preventing grey hair.
This isn't a vitamin or a mineral, it's an essential amino acid. As well as being vital for keratin production, studies show that L-methionine can slow the onset of grey hair by fighting oxidative stress.
You can get L-methionine and your other essential amino acids in protein-rich foods like legumes, pistachios, peanuts, dairy, whole grains, eggs, meat and poultry.
Should I take a supplement to stop my hair going grey?
Generally speaking, it's easier for your body to absorb minerals and vitamins from the foods they naturally occur in. That's why making sure you get a healthy intake of some the healthy, micronutrient-rich foods above is key to slowing down or reversing grey hair.
That said, several hair scientists and dermatologists do recommend taking supplements to deal with hair greying. But don't just start popping pills: first you need to be screened for deficiencies.
Even then, only certain nutrients have been repeatedly proven to stop or slow down grey hair in supplement form: Iron, vitamin D, folate, vitamin B12, and selenium were all recommended by Almohanna, Ahmed, Tsatalis and Tosti, authors of a comprehensive review on premature grey hair. "Supplementing these deficient micronutrients can improve premature graying," the researchers say.
Some supplements have been shown to combat premature grey hair where patients are deficient.
If you're low on any of the above, your doctor can start you on the correct dose. Making sure you don't oversupplement is really important as some of these micronutrients have serious side effects should you consume them in excess. Too much selenium for example, can give you hair loss.
And remember that list of extrinsic factors that lead to grey hair? Not all of them are under our control, but minimising or eliminating the ones we can influence can help hold back the march of the silver strands across your hair.