Another May bank holiday is upon us in the UK and we’re basking in the sunshine (hopefully) once more. As someone who was so badly burnt (walking in the UK countryside, whilst using sunscreen) that the marks have taken 2 years to fade, I can testify that we need to be careful with our skin. How does sunscreen work and what research is underway?
As the weather gradually improves and we hurtle towards the summer, it’s important to reiterate the importance of using sunscreen but also understand how it helps us. When our skin is exposed to ultraviolet (UV) rays from the sun, it produces vitamin D, which is essential for building and maintaining strong bones. Exposure is the main way we can get this vital vitamin, but our exposure needs differ based on skin type, time of day/year, and where you are in the world. In the UK, most people will make enough vitamin D by just going about their daily lives; no sunbathing required. Check out the Cancer Research UK website for more vitamin D/exposure guidelines. Sun damage is the most common cause of skin cancer.
Our skin has two main layers: the epidermis (on top/outside) and the dermis (the inner layer). Basal cells are a common cell type found at the bottom of the epidermis layer. This basal layer is where both normal skin cells and basal cancerous cells (BCC) come from; this is the most common skin cancer type (i.e. a non-melanoma) and easiest to treat. There is also a deeper layer of the epidermis formed by melanocytes which make melanin (i.e. the brown substance produced when exposed to the sun). If these cells become cancerous it is known as a melanoma. Skin cancer can be quick or slow to show signs. In 2015, there were ~142,000 cases of non-melanoma skin cancer diagnosed in the UK (many go unreported).
The sun produces UV radiation: UVB (the main cause of sunburns), UVA (penetrates the skin more deeply and contributes to skin ageing, but less to burns), and UVC (a very dangerous type but thankfully reflected back by the earth’s ozone layer). Sunburn is damage to our skin – there is no such thing as a healthy tan. It is our body’s response to try and repair itself: it is a short-term warning for possible long-term DNA damage. This Cancer Research UK video explains it perfectly.
Keeping our skin protected is vital, so how does sunscreen do this? SPF is the sun protection factor, and measures how well a sunscreen protects against burn-causing UVB rays. This number (e.g. 30+ to 50+) is based on how long it takes the sun to redden your skin when wearing the sunscreen vs. without. For example, if you become red within 10 mins in the sun (as I do), factor 50+ should give you 50 times longer. However, no sunscreen is effective for more than 2 hours without reapplication. You can get organic or inorganic sunscreens: organic ones work to absorb the UV radiation with active compounds such as oxybenzone. Whereas inorganic sunscreens, with active compounds such as zinc oxide, both absorb rays and shield the skin by reflecting some UV rays. Many sunscreens will combine both of these methods. You should ensure that you are using a broad-spectrum sunscreen to protect against all types of UV rays.
People have been experimenting with sunscreens since the 1930’s. New research is ongoing into sunscreens as it is such an important topic for every single person, and even animals! (Yes, you can get dog friendly sunscreens). There is even nanotechnology in the inorganic sunscreens we use today. Small particles (nanoparticles) are better at protecting you from UVB rays, and thus better at preventing burning. However, such small particles are not as good at protecting against UVA rays, so research is ongoing to discover the perfect balance.
There is no such thing as a safe tan. Cancer Research UK suggests a combination method to avoid skin damage: 1) find shade, 2) cover up, and 3) sunscreen. Some chemicals in sunscreens have been linked to coral reef damage amongst other things, so be sure to look out for sunscreens that state they are safe for the environment, especially when going on your more exotic holidays. Check out this National Geographic article about environmentally friendly sunscreens. This bank holiday enjoy a beer, a BBQ and a bit of sun, but remember the popular Baz Luhrmann song, and trust me on the sunscreen.