As a continuation from last week, I have provided yet more ingredients you should be looking for in your beauty products. This week focuses on green tea extract and salicylic acid, their benefits and their flaws.
Green Tea Extract (Epigallocatechin Gallate)
The first thing they teach you in MRes Toxicology is “do not sniff the chemicals”. Next up in Tox101 is pretty much everything is toxic, to some extent. Hell, you can even kill yourself by drinking six litres of pure water, a substance that makes about 55% of our bodies.
One of the more striking examples is green tea extract. You might very well have rubbed it all over your face, drunk a bit, and even consumed green tea supplements. What marketing isn’t too keen on letting you know the active ingredient in green tea – epigallocatechin gallate (EPCG) – is really quite bad for your liver. When it’s in your bloodstream, liver enzymes metabolise it to a toxin that causes scarring and cellular death.
Now for the good news. A cup of green tea doesn’t usually contain enough epigallocatechin gallate to cause any problems, and it’s absorbed too slowly through the skin to cause any damage. The only way for EPCG to damage your liver is through “green tea supplements” – little pills often touted by nutritionists with only a passing relationship to science. In fact, EPCG can be very good for your skin. When absorbed by your skin it acts as an antioxidant, reducing the chances of receiving DNA damage from UV light. This means less sunburn and less chance of developing a melanoma (skin cancer). The enzymes used to break EPCG down into toxins aren’t usually found in your skin, so it does little harm.
I’ve seen people say salicylic acid is good for your skin. Those people probably attended the first thirty seconds of a presentation on human papilloma virus treatments before getting bored and trying to develop hand soap from bleach. What I mean is that in some situations it is good for your skin, but in others, not great.
Salicylic acid is used primarily as a treatment for common warts and acne, as well as more uncommon genetic skin conditions like psoriasis and ichthyosis. At high concentrations it can cause skin burns; don’t use wart treatments to get rid of your acne, unless you’re unreasonably confident in your dilution capabilities.
At very low concentrations it’s used as an exfoliating agent; it helps remove dead skin cells from the surface, making it look clearer. Exfoliating is good for you to some extent, especially if you have acne; you remove more Cutibacterium acnes and Staphylococcus epidermidis bacteria versus just washing with a sponge. If you don’t have acne, you’re just removing the outer layer of skin for cosmetic effect, which makes it a little easier for germs to get in. Also, by removing the outer layer of your skin you increase your risk of sunburn and skin cancer from UV; not so much of a problem during the winter months, but something to bear in mind during the summer.
Oh, and if you’re under nineteen be wary about using it, especially if you have a fever. Salicylic acid has been linked to Reye’s syndrome, along with aspirin. However, if you suffer with acne and have been prescribed salicylic acid by a doctor, then you can use it under the age of nineteen.