Scientists have discovered that totally blind women had a 36 per cent lower
risk of breast cancer compared with sighted women. Women who became blind
relatively early in life (before the age of 65) appeared to be especially
protected against breast cancer, with incidence rates 49 per cent below those of
sighted women.
Only total blindness, not visual impairment, seemed to protect against breast
cancer. According to the authors, this supports the theory that increased
night-time exposure to artificial light reduces melatonin levels, altering
estrogen secretion rates and raising the risks of breast cancer.
Melatonin, which is secreted by the pineal gland in the brain and plays an
important role in the body’s sleep cycle, is thought to influence the secretion
of estrogen. The latter in turn affects the risk of cancer.
Blind women are by definition unreceptive to light. However they maintain
high melatonin production at night regardless of external light conditions. The
British Journal of Cancer (March 2001; 84:397-399) added that researchers
believe that this may be the mechanism whereby blind women are protected from
breast cancer.
Information provided is courtesy of and compiled by the Academy of Anti-aging
Research staff, editors, and other reports.
