Circadian rhythms, sleep and their impact on skin

Characteristically, though not always so, the products have a heavier texture from using a higher content of richer emollients, giving the consumer the perception that the skin is being fed and nourished, working its magic while we sleep. Certainly in terms of moisturisation, softness and firming these effects are well documented. In fact the effects of sleep itself on our appearance are well ingrained in popular culture, the phrase “Beauty Sleep” has been in use for well over a hundred years, being defined in an 1890 dictionary of slang as: “Sleep before midnight, on the belief that early sleep hours conduce to health and beauty”1 and included in many novels of the early twentieth century, for example “But eager as Kate was for her beauty sleep, the light burned late in her room.”2

If we do suffer from a restriction in our time asleep the effects on our appearance and our skin often manifest themselves very quickly. It is not unusual to overhear people make comments such as “You look tired today!”, or “Have you not been sleeping well?” both of which indicate how easily we innately pick up on the signs of a lack of sleep. This also indicates how very good the skin works as a signalling organ, giving insights into our current state of health and wellbeing.

The functions of our skin can be described as being circadian (derived from the Latin – Circa(about) and diem (day)), they follow a twenty four hour cycle during which the skin alters its primary function depending on what part of that cycle it is in. The basic rule for the skin is that during the day its objective is protection whilst at night it is repair. Further, more specific details on this are given below.