title: Regular sun exposure benefits health.
abstract: Since it was discovered that UV radiation was the main environmental cause of skin cancer, primary prevention programs have been started. These programs advise to avoid exposure to sunlight. However, the question arises whether sun-shunning behaviour might have an effect on general health. During the last decades new favourable associations between sunlight and disease have been discovered. There is growing observational and experimental evidence that regular exposure to sunlight contributes to the prevention of colon-, breast-, prostate cancer, non-Hodgkin lymphoma, multiple sclerosis, hypertension and diabetes. Initially, these beneficial effects were ascribed to vitamin D. Recently it became evident that immunomodulation, the formation of nitric oxide, melatonin, serotonin, and the effect of (sun)light on circadian clocks, are involved as well. In Europe (above 50 degrees north latitude), the risk of skin cancer (particularly melanoma) is mainly caused by an intermittent pattern of exposure, while regular exposure confers a relatively low risk. The available data on the negative and positive effects of sun exposure are discussed. Considering these data we hypothesize that regular sun exposure benefits health.
authors.affiliation: Department of Dermatology, Haga Teaching Hospital, Leyweg 275, 2545 CH Den Haag, The Netherlands. Electronic address: hvdrhee@casema.nl.
authors.forename: H J
authors.initials: HJ
authors.lastname: van der Rhee
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Pontificia Universidad Javeriana, Bogota, Carrera 7 No. 40-62, Colombia; Department of Public Health, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: de Vries
authors.affiliation: Department of Public Health, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Coebergh
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D004781:Environmental Exposure; D005060:Europe; D005260:Female; D006262:Health; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology; D008550:Melatonin / Q000378:metabolism; D051379:Mice; D009368:Neoplasm Transplantation; D009569:Nitric Oxide / Q000378:metabolism; D012307:Risk Factors; D012701:Serotonin / Q000378:metabolism; D012878:Skin Neoplasms / Q000473:pathology; D013472:Sunlight; D014466:Ultraviolet Rays; D014807:Vitamin D / Q000096:biosynthesis
chemical_list: D014807:Vitamin D; D009569:Nitric Oxide; D012701:Serotonin; D008550:Melatonin