Date: Mon, 24 Jul 1995 01:43:55 -0800
From: Peggy Wilbur <moon2peg.SLIP.NET>
Subject: Re: wild yams
I have been away from the list for some time (due to lots of study and work), but have been reading mail when I have a chance. I do have to jump in on this one, though, because I feel that it is important to nip this one in the bud. The following is based on my own extensive research on phytoestrogens. While my research has led me deep into the chemistry of phytoestrogens and the physiology of the endocrine system, I keep it very basic here...In reply to:
Deb Phillips wrote:
> msmith.OLDCOLO.COM (Candice Smith) writes:
>>I recently read an article about the use of wild yam in gel caps as a form of birth control. The article warned that it is only effective if taken in regular doses (3 size 00 capsules twice a day) and then you have to wait 2 months before it works. I would be willing to try it--I've had a horrible time with conventional birth control, but the article had no references or explaination of how the wild yams work. Has anyone else heard of this? I'd appreciate any info.
>I had heard from my midwife that they worked for birth control. I asked the group but did not get much discussion on it. I would be interested if someone knows the action there also.
Wild Yam, (Dioscorea villosa), contains a number of substances known as phytoestrogens. Phytoestrogens are those plant chemicals that bind to our cells' estrogen receptor sites and, theoretically, trigger the components of estrogenic activity (activity does not necessarily mean production). This binding is possible due to striking similarities, in shape and structure, to the body's own steroids. By binding to these estrogen receptor sites when blood estrogen levels are high, phytoestrogens are, again theoretically, able to reduce overall estrogen activity (Key to the estrogen-induced breast cancer debate). Conversely, when estrogen levels are low, they are able to promote estrogenic action.
Well over 250 plant species contain phytoestrogens, including, for example, Dong quai (Angelica sinensis), Red clover (Trifolium praetens), Alfalfa (Medicago sativum), Licorice root (Glycyrrhiza glabra), Fennel (Foeniculum vulgare), Black Cohosh (Cimicifuga racemosa), and Soybean (Glycine max). There is much controvery surrounding the uses of such plants both medicinally and nutritionally.
Some herbalists (and others) believe that the phytoestrogens found in the Wild Yam, including steroidal saponins (mainly diosgenin), are hormone "precursors", especially of progesterone. However, while diosgenin from D. villosa (Not from D. villosa - wildyam - but from another species -- Henriette) was once widely used, through an industrial five-step chemical degradation (e.g. the Marker degredation), in the industry manufacturing of progesterone-containing birth control pills, the human body is not capable of such a synthesis using phytoestrogens as a starting point. Our bodies simply do not have the enzymes necessary for such a "building block" conversion. The estrogenic effects that have been noted (i.e. in relation to relief of various menopausal discomforts) may very well be due to the previously mentioned binding of phytoestrogens to estrogen receptor sites, which occurs when phytosterols cross the cell membrane and bind to a specific cytoplasmic receptor molecule. The receptor-hormone combination then enters the nucleus, where it binds to a particular DNA sequence by attaching itself to a specific site on a chromosome. This attachment activates those genes responsible for hormone-induced changes. (It gets a bit more complicated than this, but I'll spare you!)
So again, while some steroids are bioconverted or biosynthesized through the metabolic action of the liver to produce sex hormones (i.e. cholesterol > estradiol), the liver does not produce estrogen or progesterone by "building" upon the diosgenin in D. villosa.
Very brief, but hope this is of some use to you both. Wild Yam does not act as a birth control pill just because birth control pills were once synthesized from its constituents. While some women may write back and say that the Yam has been effective for them, I might ask what other factors may be at play in their lives that may be responsible for a lack of pregnancy.
Thanks for reading this long reply.
From: Peggy Wilbur <moon2peg.SLIP.NET>
Hello Peter, and all,
First, thanks to those of you who have written to welcome me back. Your comments are much appreciated.
In response to the following:
>I can understand the reasons why you think wild yam would not work as a form of birth control, but your belief is based on theory, in vitro experiments, animal experiments etc. and not on practice, and not in human beings.
Actually, Peter, I agree. An entire chapter of my study is dedicated to questioning the relevance of in vitro and animal experiments in relation to my inquiry. The very idea that studies testing the effects of an herb on a women's endocrine/nervous system are done on animals that do not even menstruate is, and has always been, beyond me. I purposefully sought out human clinical trials and studies in my research, using "human clinical" as part of my search strings. What I found was that some of the studies only involved six women, or involved women who were on vegetarian diets in which they consumed large amounts of soy and legumes and tended to ingest many other herbs as part of their everyday diets (Consumption of soy products (soy also contains phyto-estrogens) in traditional Japanese diets is thought to play a part in lower breast cancer rates--this belief stems from human clinical evidence.
>I would be more likely to believe empirical evidence (people who have successfully used it, like my wife) than on a theory about what a few of the compounds in the yam are "supposed" to do.
One reason why I became so interested in this subject is that I have a very close friend who became pregnant WHILE using the yam, as directed, and had to go through the pain of an abortion.
>If the experimental evidence doesn't support the observations, then not all of the variables have been considered by the experimenters.
I strongly believe that, in the scientific testing of herbs, this is usually the case. Scientists (and I admit that I am a scientist myself, but I am also an herbalist - I do not see the two as opposite sides of a coin) often tend to look for particular types of constituents (i.e. alkaloids) and base efficacy and lethal dosage on results found only within a particular scientific construct. In other words, quite often, the cards are stacked before $500,000 and the lives of millions of lab animals are wasted trying to prove, within biased guidelines, that the herbs work.
>Don't be so quick to assume that people for whom this has worked are too ignorant to account for "other factors [that] may be at play in their lives that may be responsible for a lack of pregnancy."
Please, sir, I never used the word ignorant, nor would I ever cry ignorance in this case. I, perhaps failingly, tried to suggest that the complexities of this question merit an examination of the other factors that may be in play in a woman's life that would explain infertility in a woman taking wild yam as birth control.
I feel that I made it quite clear that the assumption that yams contain "progesterone building blocks" (based on the fact that the yam was made to produce, industrially, birth control pills) is of main concern. The fact that phyto-estrogens have strikingly similar shapes to our bodies own steroids--and cholesterol, by the way--seems to allow them to be shown the way to estrogen receptors, thereby creating an estrogenic effect on the body (which is not particular, but relational) It is important to remember that receptors get saturated or filled (i.e. if you take a dose of LSD today, the same dose may not create a psychadelic experience tomorrow, but might the day after), so if the body's hormonal homeostasis is comfortable or "normal" (tricky word, I know), in other words, if estrogen levels are not considered "high" or "low", one may not notice a difference. But, if levels are low, the phyto-estrogens may fill receptor sites, thereby "normalizing" estrogenic activity - if high (as in breast cancer, etc.), the phyto-estrogens may, by filling the sites, result in the brain's not triggering the production of even more estrogen.
It is interesting that in some of the older studies, the discovery of phyto-estrogens made some in the research community question whether we should be eating foods containing PEs at all! (For fear of "increasing" estrogen in the body) Now that the receptor site activity is understood a bit more, it is being proposed that PEs be included as part of the US Recommended Daily Allowance in vitamins! Yes, for men too.
>As far as I'm concerned, the burden of proof is on the researchers, not on the people who are able to get the desired results.
I am truly glad that you have been able to avoid unwanted pregnancy. This has not been the case for all of us.
With deepest respect,