Analgesic use may decrease postmenopausal estrogen levels

Postmenopausal women who regularly use painkillers have lower estrogen levels, which could lead to a decreased risk of breast or ovarian cancer, according to researchers at Boston's Brigham and Women's Hospital and Harvard Medical School (Cancer Epidemiol Biomarkers Prev online, March 23, 2010).

The investigators looked at the link between the use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and acetaminophen and concentrations of estrogens and androgens among 740 postmenopausal women who participated in the Nurses' Health Study. The frequency of all analgesic use was inversely associated with estradiol, free estradiol, estrone sulfate, and the ratio of estradiol to testosterone. The average estradiol levels were 10.5% lower among women who regularly used aspirin or non-aspirin NSAIDs. Free estradiol levels were 10.6% lower and estrone sulfate levels were 11.1% lower among regular users of aspirin.