Skin aging

The skin has the capacity to renew itself every 28 days. With age, this process increases to more than 30 days. Older cells accumulate, the sebaceous glands play their role less effectively, and the number of melanocytes decreases. This is the process of skin ageing, also known as senescence. 
There are several factors responsible for skin ageing: internal factors such as genetics, which cannot be changed, and external factors (sun exposure, diet, etc.) which facilitate the release of free radicals and accelerate skin ageing.