This one is from Henriette, with help from unca Mike and unca Jonno.
A stubborn question, coming up on the newsgroups and mailing lists again and again: "How do you use wild yam for herbal birth control?"
Wild yam (Dioscorea villosa) does not work as a herbal birth control. People who try it invariably end up being called "Mom", unless they're naturally infertile.
So why is this myth still going strong?
Back in the early 40's the only hormones available were very expensive, injectable slaughterhouse hormones. An American, Dr. Russell Marker, had this great idea on making oral hormones from saponins (actually they're not really hormones, just hormone look-alikes - but that's another topic), and tried to get backing for research on this from the pharmaceutical companies of the time. None of these thought this worth pursuing ("we -have- hormones, enough for our needs, why would anybody want cheap oral hormones?") (which goes to show just how short-sighted people can be). Dr. Marker then went abroad, and the Mexican ministry of health said yep, sounds like a good idea. So he went to Mexico and started to look for plants with lots of saponins. Both Yucca and Agave roots contain enough saponins, and both were abundant, but neither was acceptable to the Mexican government as they were needed in the Tequila industry. So Dr. Marker settled for a plant that was abundant and easy to grow: Dioscorea mexicana, Mexican yam. It took him a couple of years to get the "Marker Degradation Process" going, and he proceeded to make progesterone, in a lab, from the saponin diosgenin found in said Mexican yam. At first the process was not economically feasible (at something like 37 steps), but when he got it down to something like 6 steps, industrial production of oral hormone look-alikes took off. And so did contraceptive pills.
A decade or three later: officials in strategic places in Mexico are looking at OPEC, thinking, "Hmmm, those guys have a monopoly -and- money, we can do that too." So they doubled the prices of the output of their oral hormone precursor factories, and whammy, next thing you see is Japanese looking around for cheap raw material - aha, soybeans. So the Japanese put up a couple of factories of their own, undercut the Mexican prices, and diosgenin the oral hormone raw material was no more. It's all soybeans now, folks.
Back then you also saw lots and lots of semi-scientific herbalists latch on to the sentence "Dioscorea is a hormone precursor". These guys and gals were totally disregarding the fact that a _lab_ is needed between raw root and hormone precursor. _People_ use cholesterols as steroid hormone precursors. The only time you're short of cholesterols is when you're reduced to skin and bones and one big belly - and if so, you've got far worse problems to worry about than an upset hormone cycle.
Now why did the name "Mexican yam" morph into things like "Mexican wild yam", "wild Mexican yam", and later on even into "wild yam" (which properly is another species altogether, Dioscorea villosa)? In the 50's and 60's Mexico fell out of fashion and, in the minds of norteamericanos, got an image as a poor country. In a stroke of genius some semi-scientific herbalists, this time exclusively from North America (at least at first), thought "we don't want any of that there imported stuff, we've got wild yam (Dioscorea villosa), let's use that".
Now, if you know your plants, you know that Dioscorea villosa is a North American plant that's been widely used as an antispasmodic (it's also called "colic root"). It has -never- been used for diosgenin extraction, nor has it therefore ever seen the inside of an oral hormone factory. It probably won't ever be used that way, either, as a) it doesn't contain enough saponins to make industrial hormone precursor manufacture worthwile, and b) it's really not all that abundant, nor all that easy to gather in quantity.
However, thus was born the name and concept of wild yam cream. Both are _completely_ off the wall, if you ask me. Be honest about it and call it progesterone cream, and tell folks just how much natural progesterone you added to that there cream, so they know in advance just how well the cream will work.
From Michael Moore:
Edible yams and sweet potatoes are simply different strains of the same plant...edible tubers of several varieties of Ipomoea batatas. NO "true yam" (Dioscorea spp.) is used in North America for food. Most Dioscoreas are about as edible as pencil shavings, with less taste.
From Thomas Mueller:
I can't recall ever tasting pencil shavings, but true yams, Dioscorea genus, are cultivated and eaten in tropical countries, and some are available in some ethnic markets in the USA. In my experience, these yams are starchy, not sweet, more like potato than sweet potato, but lower water content than potato.
From bogus.purr.demon.co.uk (Jack Campin):
And they are widely available in the UK, anywhere there's a sizable Asian or Afro-Caribbean population, i.e. pretty much any city. The smaller variety are usually called "eddoes", the large variety just "yams". Nobody calls sweet potatoes yams here any more (they probably did after WW2; that was what my father learned to call them when in the army in India and North Africa, but he unlearned it fast enough in New Zealand).
Edible yams roots are enormous. Peel, cut into chunks, boil with a bit of oil and salt. They take longer than your usual starchy vegetable to boil. They don't get all that soft. The cooking water transforms into an unappetizing whitish jelly overnight. Not really all that tasty.
Sweet potatoes, batatas, are smaller (in fact, somebody told me, long ago, the smaller the better). Peel, cut into bits, boil. Add a dash of butter - yum, tasty! The ones I've tried have all been more or less yellowish internally, with a whitish sap (sticky when dry) that turns gray on exposure to air. They're done about as fast as potatoes, and go about as soft as potatoes, too.
I expect Michael means that the North American species of Dioscorea do not sport edible roots.
Wild yam (Dioscorea villosa) as such does not contain progesterone nor anything else that would act like progesterone. It's a good antispasmodic, and that's it. So, unless your menopausal symptoms include lots of cramps wild yam won't do squat for them.
The "wild yam" creams that work for menopausal symptoms (like hot flashes) contain synthetic natural progesterone. Natural progesterone is a pharmaceutical term. It doesn't mean that the progesterone is plant-derived, nor that the plants it possibly is derived from are organically grown - it means that the progesterone is identical to the human hormone progesterone. Natural progesterone is all synthetical, i.e. you need a lab to manufacture it from your raw materials. Unless, of course, it's extracted from animal glands, in which case it's not identical to our own progesterone (vide the allergic reactions from animal-derived conjugated hormones), and should be called something else.
How come these creams can contain synthetic progesterone without that being stated on the label? Natural progesterone is considered a cosmetic in the USA, because the FDA doesn't recognize that topical progesterone works ("just look at those women, they'll believe -anything- ..."). Labeling of cosmetics is rather loose, and if you squint hard enough the legislation gets blurred, too. So you end up with creams labeled "wild yam extract" or something equally unlikely. This might be bordering on the illegal, particularly considering that you won't find any progesterone derived from wild yam (Dioscorea villosa) on the market.
Like I said, be honest about it and call it progesterone cream, -and- add amounts to your labels.
For further reading you can try John Lee's book "Natural progesterone, the many roles of a wonderful hormone". He's also written "What your doctor may not tell you about menopause". I don't have either so can't say how good they are.