Shedding Light on Skin Cancer
Tue, 19 December 2017
Humans confuse the sun’s health benefits with harmful effects. Anne of RAspect decrypts the solar code
Ancient cultures worshipped the sun for its life-giving warmth and powerful healing energy. They knew that the sun could be dangerous, but fundamentally it was praised, respected and revered as the source of life.
In recent times, we’ve focused heavily on the dangerous aspects of sunlight. The science of how sunburn, the result of overexposure to UVA and UVB radiation, can cause the formation of DNA-damaging molecules, leading to skin cancers, premature aging of the skin, and cataracts, is well understood and widely accepted. We are especially aware that excessive UV radiation (sunburn) can increase our risk of developing deadly malignant melanoma.
Public health messages urge us to be “sunsmart” and remain vigilant against the dangers of the sun. The consistent message on this topic for the past 50 years is to avoid intentionally exposing ourselves to sunlight, and to cover up with high factor chemical sunscreen when being out in the sun is unavoidable.
Ironically, it turns out that we’re mostly in the dark on the subject of sunshine. The effectiveness of these warnings has resulted in excessive sun avoidance behaviour – which turns out to be more dangerous than UV radiation itself.
Our body’s best defence against skin cancer – by far – comes in the form of vitamin D. Produced naturally in our bodies when exposed to UV radiation, vitamin D governs an impressive range of natural defences against DNA damage from UV radiation, and has a host of other vitally important roles in overall health.
Put simply, regular non-burning exposure to the sun helps keep you healthy generally, and triggers the normal functioning of your body’s own evolved defenses against sun damage specifically. Conversely, abstaining from exposure to the sun inhibits these natural mechanisms; and occasional sun exposure on underexposed skin is far more likely to cause serious harm.
Your best defence against sun damage is to regularly spend time in the sun. Clearly, we should avoid becoming sunburned. The pain and redness associated with it are obvious signals that we’ve done ourselves harm. It is true that sustaining a sunburn increases your risk of developing melanoma. But it is equally true that being in the sun regularly, decreases that risk significantly. The solution is not to avoid sunshine. We evolved in the sunshine, and our bodies both thrive in and require it to function properly.
Today, spending too little time in the sun is a far more common and serious threat to human health than the converse. Excessive UV radiation accounts for only 0.1% of the total global burden of disease, while Vitamin D deficiency is a major public health problem worldwide in all age groups. And again, sunburn is much more likely to occur on skin that is not normally exposed to the sun.
It’s been shown by numerous studies that regular time in the sun protects against a number of diseases, including malignant melanoma and a range of other cancers. Most melanomas occur on the parts of the body least exposed to the sun, and among those people with the least sunshine in their lives. It is well recognized in the scientific literature that regular exposure to sunshine both reduces the risk of developing melanoma, and increases the chances of recovering from it.
The link between exposure to the sun and a lower chance of dying from cancer has been noted since the 1960s, and the exact role of vitamin D started getting attention in the 80s. Despite this, the standard advice – namely to avoid intentionally exposing skin to the sun and to use chemical sunscreens for protection – has only intensified. Scientists writing in the journal of Dermatoendocrinology in 2016, state that these public health messages, along with our increasingly indoor lifestyles, have likely contributed significantly to the massive increase in cases of melanoma over the past 50 years. They have literally helped keep us in the dark, to our peril.
Using chemical sunscreen is not the answer either. The 2016 review of the risks and benefits of sun exposure states unequivocally that “we can find no consistent evidence that use of chemical sunscreens reduces the risk of melanoma”. The review goes even further, recommending that sunscreen labels “should contain a statement about the possibility of vitamin D deficiency that may result from excessive use of sunscreens. Labeling should also state that sunscreens have not been shown to be effective in reducing the risk of melanoma.”
Numerous studies confirm that regular exposure is protective against melanoma and a host of other cancers and diseases. Sunshine also improves your chances of surviving and recovering from these diseases, including melanoma.
Let’s be very clear: for most healthy people – and even a lot of unhealthy people – sunburn is bad, being out in the sunshine is not. So go on, step into the light!