Adapting to the Sun.

Following on from yesterdays overview ‘Our Place Under The Sun’ today I want to explore the body/ sun relationship in a bid to find out if the perfect sunscreen can even exist.

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Plant a water-lily in the desert and it will get sunburn. Plant desert cacti in the rainforest and its roots will soon rot.

Why is it that we now seem to see the sun as something dangerous? Is it something to be feared and avoided at all costs? Will age you, give you cancer and cause your immune system to go into free-fall? A quick look through the blog posts coming out of the northern hemisphere would lead you to thinking that we are waging a war against the sun. I wanted to find out how something once revered is now vilified and in order to do that I thought it best to start at the very beginning.

Melanin.

Desert dwelling cacti have evolved to deal with the suns full force. They have no leaves to preserve water and use hairs, spines and sometimes wax to protect them from the sun. So, it would seem that plants do indeed wear sunscreen. 
The problem that people have is our desire to explore and our natural sunscreen may not be able to keep pace with our sense of adventure. We invented boats, trains then planes to take us everywhere. While this travelling has proved to be of great benefit to humankind, it has contributed to our sun-hate relationship! 
Take me for example. I have a skin type of 1 according to the Fitzpatrick scale – just call me burney! I chose to move to Australia with my family five years ago and while the intensity of the sun did lead me to think “is this wise for someone so melanin deficient?” I, along with my equally white family decided to come anyway. Now if I were a plant I would have shriveled and died by now without lots of care, as a person I have managed to live in near perfect harmony with the sun until now. BUT to do that comes with strings attached.

Looking at this it would seem that the problem lies not in the sun but with our wanderlust, many of us are simply living in the wrong place for our skin! But we want choice with regards to where we live, need it, thrive with it  even and so dutifully crawling back under our rocks or gliding back to our deserts is not the way to go. We just need to deal with it.

The Ever Changing Sun. 

The sun is not static in this equation, its power ebbs and flows with each hour, day, month and year. In addition, the energy that reaches us from the sun is affected by pollution and has been changed somewhat thanks to the hole in the ozone layer that sits right over Australia and New Zealand.  We really do need to think about this!

Evolution takes a long time, far longer than it takes for man to create a new chemical or process and therefore as the pollution and ozone hole that we now live under are relatively new we have little natural protection from them.  Between the mid nineties and mid 2000’s one study looking at MED’s (Minimal erythema doses or time it takes to burn)  noticed a distinct drop in time.  For example someone who in 1995 took 10 minutes to burn was burning in only 7 minutes ten years later.   This small study drew attention to the fact that something might be happening out there and more importantly, our bodies weren’t prepared for it.  Maybe that’s why despite people wearing sunscreens more nowadays some types of skin cancer are still on the rise.

The ozone layer is a gaseous barrier that surrounds the earth, shielding us from the bulk of UVB irradiation and making it possible for life as we know it to continue. Strip the ozone layer away and we would fry as would many plants and animals who have also evolved with little natural protection against the sun in all it’s non-abaited glory.   The ‘hole’ is actually changing the quality of UV radiation that reaches us and that is bad news as this change in quality has the same effect on our bodies as moving us to a whole new planet – we just aren’t equip for it.

So is there any hope of making the perfect sunscreen?

So, melanin is our natural sunscreen and as such is the bodies ‘perfect’ sunscreen in as much as it evolved both to protect us and help us thrive.  However, the sun that reaches us is forever changing thanks in part to our activities here on earth and as such it looks likely that there is no real chance of us evolving or creating a situation of perfect skin/ sun harmony.   Manufacturers are currently looking at a number of ways of boosting our skins natural SPF including oral supplements, special diets, antioxidants, vitamins and essential fatty acids built into sunscreens and sunscreens with broader UV coverage but all of these have limits. It looks likely that in this modern world with ozone holes, global travel and atmospheric pollution us formulators will have to use every trick in the book to keep us safe, well and able to claim our place under the sun.  What a challenge!

Tomorrow we will look at how our skin uses the sun for good as we explore the wonderful world of vitamin D.