In the midst of this lovely summer weather we’ve been having lately, I’ve spent the last few days hiding from the sun. Yes, hiding, not bathing in its golden light, occasionally rolling over to tan another part of my body, soaking up that vitamin D, but retreating into the shade, covering my ghostly white face with a large hat, and slathering on the factor 30. Although I might seem more than a little bit paranoid, I’m not (entirely) crazy for doing this. Sun damage is not only unpleasant, both to look at and to feel, but too much of it can be dangerous, potentially even leading to skin cancer. The UV radiation which accompanies the light from the sun can cause the DNA in our skin cells to mutate, and these changes can be deadly, allowing cells to grow rapidly and uncontrollably, with the sun’s radiation leading to around 90% of cases of skin cancer.
But the sun isn’t all bad. Most of us are dependent on sunlight to gain our intake of vitamin D, a vitamin which is important for the absorption of calcium, which most of us know is required for strong, healthy bones. When our skin absorbs UV light from the sun, a cholesterol in our skin is converted into a precursor for vitamin D and then eventually into the active form of vitamin D itself. When we don’t produce enough vitamin D, we become deficient, and this can lead to rickets in children, and osteoporosis in adults. Of course, spending time in the sun isn’t the only way we can increase our levels of vitamin D; it’s also found in oily fish, eggs, and vitamin supplements.
But vitamin D isn’t the only thing the sun has to offer us. Seasonal affective disorder or “winter depression” is a disorder characterised by low moods and lack of interest in activities during the winter months, symptoms of which decrease and eventually disappear in springtime. This condition is currently poorly understood, but one possible explanation is that depressive episodes in those affected might be related to the decrease in sunlight during the winter months. Since during winter our skin is less exposed to the sun and sunlight hours are short (although you can still get sunburn in winter, as many skiers will have experienced), this can affect not only our levels of vitamin D, but a number of other hormones in our body, including melatonin and serotonin.
Melatonin is involved in regulating sleep; as it gets darker, and closer to night time, levels of melatonin in our body increase, making us feel sleepy. During winter, when night time falls earlier, and the days can be darker, some people produce higher than usual levels of melatonin, as they are exposed to less sunlight, therefore reducing the production of melatonin. Serotonin is a hormone which affects mood, appetite and sleep, and in people with seasonal affective disorder, levels of serotonin drop during the winter, which could contribute to feelings of depression. So while the sun can be dangerous, it’s also very important for regulating our moods. Who hasn’t felt just a little bit happier after stepping outside the house to see what a nice day it is?
The level of damage the sun causes us, and the amount of time we can afford to spend in the sun to reap its health benefits, depends on several factors. People with darker skin have higher levels of a pigment called melanin, and this is thought to have arisen in populations which have been more exposed to the sun in their evolutionary history, giving them higher levels of protection from UV damage than those with lighter skin and lower levels of melanin. Studies have shown that incidences of skin cancer are higher in those with lighter skin than in those with darker skin, backing up this idea that this pigment provides some protection against the damaged caused by increased sun exposure, almost like a built-in sun cream. What a lot of people don’t know however, is that even if you’re the kind of person who doesn’t burn in the sun, but instead find yourself getting a tan (something I can’t say I’ve ever experienced), this is still a form of sun damage, and can still cause you harm, even though you won’t look as ridiculous than your friend with the red nose and cheeks. Some studies have found that eating lots of tomatoes can increase your protection from the sun, as they contain an antioxidant called lycopene, which is best found in tomato paste, although I wouldn’t start eating tomatoes in the place of wearing sun cream just yet.
So, the sun, the star that our planet orbits around, that gives us seasons, the hours of the day, and our light to see by can also have huge impacts on our health, from its effects on our mental health to our physical health. As with anything, too much of a good thing can be very bad for you, but it’s hard to find the balance between enjoying the sun, and keeping our skin safe, particularly when the sun and all those thoughts of picnics and outdoor sports are so much more inviting than a darkened room. If you’re in Britain, I say enjoy the sun while it lasts – you might not see much more of it! But it might be worth putting on a little bit of sun-cream, if nothing else, so that you don’t end the day with everyone laughing at your sunglasses marks.
Thanks for reading, let me know what you thought of this post in the comments below! Hope you’re enjoying the start of summer (or winter, if you’re in the southern hemisphere).