Click below to watch an interesting story that was shown recently on the ABC television program Catalyst.
A good quality sunscreen should be the first purchase in your skincare range and will have a greater effect on skin health than the most expensive serums and creams. But before I discuss the classification of sunscreens and their advantages and disadvantages, I need to talk about the different types of UV light that can affect human skin.
I’m sorry, but we need a bit of science here. I’m sure a lot of people know this already, but it is important to make the most informed choice.
The main types of UV light we need to be concerned with are UVA and UVB. UVA light penetrates more deeply into the skin than UVB and is responsible for causing photo ageing and wrinkling. It also probably initiates and exacerbates some skin cancers. UVB causes sunburn, tanning, also some photo ageing, and has a major role in the development of skin cancers.
UVB exposure will vary depending on the time of the day, the season and the latitude.UVA exposure is constant and, unlike UVB, does penetrate glass. Clearly, we need to protect against both types.
Sunscreens are divided into 2 main categories – physical and chemical. Physical sunscreens work by reflecting the UV light away from the skin. Chemical sunscreens are absorbed into the epidermis and then absorb the UV light.
Physical sunscreens will protect against UVA and UVB. These include zinc oxide and titanium dioxide(titanium dioxide protects against UVB and some UVA and zinc oxide gives complete cover for both) . They are less irritating to a sensitive skin than chemical sunscreens, but can be quite thick and opaque on application. This cosmetic concern has been partly addressed in some products by reducing the size of the particles to tiny fragments known as nano particles. It is still not quite clear if nano particles can be a problem, as small amounts of these products can be detected in blood and urine days after application. The TGA declares that there has been no unique nanotechnology specific health hazard identified. More research is needed here.
There are a number of different active ingredients that can be added to chemical sunscreens. For this reason, they are more likely to irritate sensitive skins, aggravate acne and cause allergic reactions. Only some give UVA as well as UVB protection, therefore it is important to check that the sunscreen provides both. The SPF rating only relates to UVB exposure and has nothing to do with UVA. There is also some controversy over whether some of these chemicals may in fact cause long term health problems, including skin cancer, by formation of free radicals. Again – more research is needed.
Another difference between the two relates to the onset of action. A physical sunscreen is effective as soon as it is applied and a chemical product will take 20-30 minutes for absorption before it is safe to go into the sun. No matter what type of sunscreen is used, however, it is important to apply enough product to cover the area adequately and to reapply frequently, more so if swimming, and then using a product with water resistance.
I recommend using sunscreen to the face and any other sun exposed areas every day, as part of your daily routine. I do this myself, regardless of the weather or what I am doing. I only wish I had started earlier. I do have a lot of sun damage on my body from my teenage sun-baking. We now know that the sun we see in our youth has the greatest impact on the skin with respect to increasing cancer risk and sun damage. Having said that, it is still essential to prevent as much further damage as possible.
If you have concerns about sun damage now, there certainly are treatments to improve the appearance of the skin and also, using photodynamic therapy (PDT), to reduce progression of silent premalignant lesions to skin cancer.
Click on the image below to view a video on PDT treatment.
If you would like to discuss any of these issues further, or would like a complimentary skin assessment with individualised recommendations, please call or email us at Shine.