Why does sunlight make skin darker and hair lighter

Being there under the sun light comes with lot of benefits. It acts as a good source of vitamin D, energizes ourselves. Along with this, there is a lot of different effect it has us. Like, it darkens the skin when exposed to sunlight for long time but at the same time, it lightens the hair. But why the opposite behavior? Let's find out!

Well, obviously one needs to be under the sun for a long amount of time for this to happen. But why exactly does this happen?? Let's put it this way, our skin is able to protect itself from the sun however not so much can be said about the hair. No, this is not a joke!! Let's understand this further..

So the basic reason for any color is called a pigment called melanin. Melanin is a pigment found in the hair and skin which is the reason for the darker color. The special cells in our skin called melanocytes make two different types of melanin. Eumelanin which gives brown or black color and Pheomelanin which gives yellowish red. The amount or concentration of each melanin type decides the color of the skin and hair.

Now, we all are aware of the fact that sunlight comes with the harmful UV rays too which is harmful for us! Now the rays do affect us by destroying the melanin when exposed over prolonged exposure. Because melanin works like a protective layer for us against the harmful UV rays. Degradation or destruction of melanin happens at both the skin and hair.

Now the main difference lies here.. 

Skin cells are alive, so they respond to the harmful UV rays by asking the body to make increase the melanin production to give more protection. Thus, there is an overcrowding of melanin on the upper layer of the skin making it darker. Over the period of time, continuous exposure is what gives the skin tan.

On the other hand, hair cells are basically dead cells having water, lipids, proteins etc which means they cannot respond for protection hence the damage cannot be reversed similar to what happens on the skin. So basically until the next hair strand comes out, the hair color stays lightened.

So, just the difference lies in whether the cells are alive or dead which decides whether the exposure to the sun would make the color darker or lighter.

Over exposure of harmful UV light rays is said to sometimes lead to increase in risk of skin cancer. So make sure you take care of the skin using some protective layers used. 

Well, that's it for the curious mind for now.. Until next time.. remember to make the curiosity work its wonders.

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