I just got reacquainted with Skin Nutrition’s Cell CPR after buying a replacement bottle and was reminded that amongst its 70-odd ingredients is wild yam. This jumped out at me because a friend had just emailed me a couple of links about wild yam and controversial claims that it can harness hormones to relieve symptoms of menopause, cure arthritis and even enlarge breasts. Sounds like a little Truth In Aging perspective is in order.

The roots of wild yam (dioscorea villosa) and claims for its medicinal prowess date back to the 1960s. Wild yam contains something called diosgenin and it was discovered that this is the precursor for the semisynthesis of progesterone. By converting diosgenin in the lab to progesterone, scientists produced the first combined oral contraceptive pills.

It was a small step for snake oil salesmen to say that wild yam contains progesterone ergo if you rub this wild yam cream on your breasts they will get bigger. They won’t. Wild yam doesn’t actually contain progesterone and the body cannot change diosgenin into progesterone; it has to be done in a lab.

Still if you are willing to stick with your Wonderbra, wild yam and its diosgenin, a steroid saponin, have plenty of other things to offer.  Some of wild yam’s benefits may, or may not, be due to estrogen. Some sources say that there is no estrogen in wild yam diosgenin. Whilst others, admit that it is present but not necessarily readily converted by the human body – although the effects of estrogen and progesterone have been shown on mice.

Despite the debate, there does seem to be credible research showing that wild yam is beneficial for post menopausal women. For example, a study on 22 women who ate yam for 30 days, replacing two thirds of staple food, showed improved status of sex hormones, lipids, and antioxidants. The researchers speculated that these effects might reduce the risk of breast cancer and cardiovascular diseases in postmenopausal women, although they admitted that “the exact mechanism is not clear”.

Aging women might also be interested to learn that wild yam may prevent the decline of bone density:  one study concluded possible therapeutic use of diosgenin for the treatment of certain bone-related diseases and another study that found diosgenin to be a treatment for osteoporosis. Diosgenin is also found in other plants, such as fenugreek, and research has found that the fenugreek constituent diosgenin seems to have potential as a novel colon cancer preventive agent.

What about its role in skincare? Well, it seems that wild yam is worth looking out for.  A Japanese study concluded that wild yam supplements (due to the diosgenin content) resulted in the “restoration of keratinocyte proliferation in aged skin”. And it may be useful against sun spots - a 2007 study concluded that diosgenin inhibits melanogenesis and “may be an effective inhibitor of hyperpigmentation”.