Daniel W. Cramer and colleagues at Brigham and Women’s Hospital in Boston (US) have found a dose-related link between women’s consumption of coffee and their levels of oestradiol (a naturally occurring form of oestrogen) during days 1-5 of their menstrual cycle. The study covered nearly 500 women aged 36 to 45 who were not pregnant, breast-feeding or taking hormones.

They recommended any woman with endometriosis, breast pain or family histories of breast or ovarian cancer, especially arising premenopausally, to limit consumption to two cups a day. Raised oestrogen levels have been linked with all of these female diseases.