Why does light help acne?
Most people who have tried will agree that natural sunlight seems to have a beneficial effect on their skin and reduces severity of spots. Why does this happen?
Sunlight itself contains a wide spectrum of light, parts of which are beneficial and other parts which are harmful. We know that:
- Ultraviolet light (UVA & UVB), at wavelength 280nm – 400nm for example, can harm and prematurely age skin and even cause skin melanomas and worsen skin conditions. It can also sterilise the skin of bacteria, not to mention helps us to produce vitamin D and perhaps other healthy hormones.
- Pure blue light at a wavelength of 415 nm can kill a range of bacteria including Propionibacterium Acnes, the main microorganism linked to acne. While not beneficial for skin health directly, blue light doesn’t harm us like excess ultraviolet will and has been used successfully for years by dermatologists and patients looking for a solution to acne.
- Red light at 620nm and 670nm is also proven to kill a wide range of bacteria, again including Propionibacterium acnes, however the key difference over blue light is that red light is directly beneficial for our own skin health, soothing inflammation and helping with energy generation and oxidative metabolism. Essentially it harms acne bacteria while protecting our skin at the same time.