Sun’s out!

Get outside! It’s here! Quick before you miss it! There’s not been a huge number of warm sunny days but hopefully plenty to come. If you’re stuck at home this summer, you need to make sure you get outside as much as you can to get some warmth, a golden tan and some vitamin D. “Tan” is one of those words now used secondary to its original meaning as the verb, with the tanning of animal skins et cetera; so after the era when being pale and staying inside was popular, from the 1930s getting a tan was cool. Thenceforth the sun was our friend. Until a few years later when official advice was given about the damage the sun can do, increasing the likelihood of skin cancer. But let’s not get ahead of ourselves, we’ll start simple…

What is tanning?

Tanning is the process of darkening the skin colour by exposure to UV light. It involves a wee group of molecules called melanins. There are different kinds of melanins responsible for your skin colour and other coloured bits of you, like your eyes, hair, and lips. The lack of one kind of melanin with age results in those grey hairs and albinism is a condition where there’s no melanin present. Melanin is made by cells called melanocytes and then cells in the skin grab it and it sits around the nucleus to protect the DNA within from damage by radiation like UV from the sun. This explains why people living closer to the equator have darker skin as they are exposed to more UV than me, in Edinburgh, looking like a ghost! (And no, that’s not me confirming my belief in the supernatural – ghosts aren’t real…)

I won’t get too genetics involving melanin, mostly because I don’t like genetics; but a mutation has caused my eyes to be blue – lots of melanin = brown, less = green, little = blue. It’s more complicated than that but I don’t really know much more – like I say, I don’t like genetics.

504_Melanocytes
The epidermis – the top, outermost section of the skin.  Melanin is released from melanocytes at the bottom in little pods (vesicles) moving up the keratinocyte cells.  There’s far more melanin in darker-skinned people.

So tanning is all about melanin which is there to protect you; it’s a fine balance as I’ve experienced, you don’t want to be scarlet, accelerate aging or worse, be exposed to too much and maybe get cancer. For those not up on what cancer is: normal cells have a process of dying when they can’t function properly, like if DNA gets mutated (changed), and it’s stopped from making copies of itself by checkpoints. Cancer cells ignore this and keep going and dividing: they are your own cells but the code of the DNA has been changed – it won’t do its job! That’s why melanin surrounds the nucleus of the cell, stopping it being attacked. It sort of makes sense that if you’re pale and expose yourself to more UV light, you won’t have enough melanin to protect you properly.

Protecting yourself by covering up with your classy hat and sunnies works, then you’ll probably be slathering on that white coloured sun lotion. Sunscreens scatter and absorb UV light to different degrees, measured by how much longer than usual it’ll stop you being burnt. This is what that SPF (sun protection factor) indicates, so 15 SPF would protect you 15 times longer that without it. It won’t block 100% of UV light and with you moving about, sweating and diluting it, that’s why you’ll have that weird patch of burnt skin! So keep your lotion topped up, and look here for all the best advice on how to protect yourself in the sun.

The infographic below explains how sunscreens work, with the chemicals involved; also it defines the differences between specific forms of UV radiation.

Chemistry-of-Sunscreen.png

If you’re a bit pale and are tempted to get some fake tan.  This stuff wasn’t really a thing until the 1960s.  The effects of the chemical in it called DHA (dihydroxyacetone) have been known since the 1920s.  Its discovery for tanning was completely accidental in the 1950s when Eva Wittgenstein was trying to treat children with a glycogen storage disease when it spilled and stained the skin.  After research on this, the first tanning lotion was sold in the 1960s.  It works the same as the Maillard reaction which happens when meat browns when it’s baked/roasted. That doesn’t mean your arm will be nice and tender after, it only the top layers that naturally fall off that are affected, meaning you’ll have to top it up when the cells go and the tan fades. Have a look below to see the process involved.

Chemistry-of-Fake-Tan-2015-1

The ultimate consequence of being unprotected in the sun for too long is skin cancer. Cancer is a scary word, but the most common type of skin cancer is the most easily treated because it doesn’t like to spread. Melanoma is far less common but is harder to treat, it loves to spread (metastasise) and ignores a lot of treatments.  But even when I was writing this post, a new breakthrough was made by researchers in finding a way to make melanoma respond to treatments better.  So although there are aggressive cancers, there is research giving results every year that provides new targets for drug treatment that is taken advantage of; unfortunately, to ensure efficacy and safety it’s usually years before something is available for treatment.  There are some cases though, where there’s a similar drug that can help which does save lives.  You can find information about skin cancers more here and see the lovely image below which gives a nice summary of everything you need to know! Enjoy the sun but be careful – don’t look like a lobster!

Skin Cancer: UV Rays on the Rise
Advertisements

One thought on “Sun’s out!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s