A meta-analysis by Hiller et al, published in the journal Environmental Health Perspectives, suggests that spending greater than an hour a day in the sun during the summer months could decrease the risk of developing breast cancer.
Fourteen studies were included in the review and 13 in the meta-analysis, with the majority (n=8) conducted in North America. The researchers observed a decreased risk of breast cancer for individuals spending one hour or more per day in the sun during summer months over a lifetime or usual adulthood.