The thinking used to be that a tan (a complex process called melanogenesis) was the skin protecting itself from DNA damage. However, research in recent years su

The thinking used to be that a tan (a complex process called melanogenesis) was the skin protecting itself from DNA damage. However, research in recent years suggests that DNA damage has already happened at the point when tanning occurs. For example, there's this oft-cited paper: https://www.ncbi.nlm.nih.gov/m/pubmed/15748643/ https://www.ncbi.nlm.nih.gov/m/pubmed/15748643/ ("Melanogenesis: a photoprotective response to DNA damage?"). Relevant quote: "Growing evidence now suggests that UVR induced DNA photodamage, and its repair is one of the signals that stimulates melanogenesis and studies suggest that repeated exposure in skin type IV results in faster DNA repair in comparison to skin type II. These findings suggest that tanning may be a measure of inducible DNA repair capacity, and it is this rather than pigment per se which results in the lower incidence skin cancer observed in darker skinned individuals." This does seem to be the current paradigm in dermatology, and it reflects what I've been warned of by dermatologists. I've not been able to find any recent research that challenges this theory.