OVER THE RAINBOW

HOW parts of the body change colour. This week: Tongue colour changes indicate fertility TONGUE colour has long been associated with health problems — white can be a sign of oral thrush, while bright red can indicate folic acid deficiency.

But new research shows a woman’s tongue has subtle colour changes during the monthly cycle. The study, published in the Journal of Traditional and Complementary Medicine, looked at the tongues of 32 women for a month, taking pictures and corresponding them to the days of their cycles.

The results suggested that women’s tongues appeared more blue or green during the follicular phase (the first half of a woman’s cycle), compared to the luteal phase, when the tongue is redder.

It’s thought to be linked to hormones. Progesterone — which is higher during the luteal phase — triggers a warmer body temperature, which causes more blood flow to the tongue, making it appear redder, say researchers from China Medical University Hospital, Taiwan.