The problem: free radicals
In a perfect world, things are paired - Brangelina; gin and tonic; honey and soy (flavoured potato chips).
When atomic electrons are happily paired, they are (generally) stable. An atom is the fundamental unit of everything ever existed and will exist in the future. Before I have the chance to go on and talk about the physics of atomic structure (which was my worst performed subject during my undergraduate), let's just keep it simple by saying everything is made up from atoms, and the electrons in those atoms or molecules (groups of atoms) like to be paired.
When those electrons are not paired, the unpaired electron is called a free radical. It is a monster (much like a 3-year old left alone at home). It goes bouncing around and breaks things, including nucleic acids (DNA/RNA) and other cellular components. It can also un-pair other electrons in other molecules, causing a "chain reaction". Free radicals are often the culprit for pre-mature aging and in serious cases, skin cancer.
How to avoid free radicals
The short answer is we can't completely avoid free radicals. Aggravators like smoking, environmental pollutant, heat and sun exposure are things that we can avoid (or at least limit). It may be surprising, but the most common form of free radical comes from oxygen (aka reactive oxygen species) which can be produced in normal metabolism. Yup, breathing oxygen is dangerous, and it is bad for you. Free radicals also exist in the atmosphere (they exist before you breathe them in). They. Just. Exist.
Function of antioxidants
Some antioxidants work by inhibiting free radicals from forming in the first place, while others grab the unpaired electrons to prevent them from doing further damage (much like the mum who is chasing after her 3-year old).
Some common antioxidants used in skincare are:
- a variety of fruit extracts and fruit seed oils (e.g. cranberry, pomegranate, grape, etc.)
- Vitamin E
- Vitamin C
- Vitamin A (retinol)
- Green tea
Antioxidant stability and topical effectiveness
Some antioxidants are known to be rather unstable (such as Vitamin C), especially when it is exposed to air, light and heat. It is always a good idea to store antioxidants in the dark (hence the tinted bottles) and away from heat. Antioxidants can start losing their effectiveness once opened as the air in the bottle will also "oxidise" them. There is also a theory that once antioxidants are spread out on skin, they tend to immediately react with free radicals in the atmosphere and little is left to penetrate into the deeper layer in skin. Not proven, just a theory. But unless we are ready to seal our face off with glad wrap as soon as the serum/cream is on, all I would do for now is to slap some on and hope for the best.