[GorgeousBlonde]

The label on my Siriporn Premium PM says:
"Women with breast cancer or a familiar history of hormonally based cancers should first consult with a physician before using this product."

However, PM is not an xenoestrogens.

So does PM encourage breast cancer?

[Isabelle]

There is not an awful lot of research on PM yet, but the work so far indicates it's similar to hops and soy: encourage at low doses, prevent at high doses. So be sure to take enough:
http://www.sciencedirect.com/science/art...4104001667

[GorgeousBlonde]

The wording of these studies are hard to fully understand. So according to the study, how much is enough to prevent breast cancer?

[Isabelle]

Hi GorgeousBlonde,

That's because it's such a simple experiment, far away from the reality in our bodies. They just mix some breast cancer cells from the trash of the operation room with a solution of PM. This sentence is about the concentration of the solution:

"Pueraria mirifica caused proliferation at 1 μg/mL and an anti-proliferative effect on the growth of MCF-7 cells at 100 and 1000 μg/mL"

Suppose you have some 40 kg (88 lbs) of total liquid in your body. That's 40 liters. One microgram per milliliter (μg/mL) is one mg per liter. So in 40 liters, that's 40 mg. But the article says that dose makes the cancer cells grow.

Safe doses are 100 and 1000 times larger, so that's 4,000 and 40,000 mg. Those are stalling doses. Unfortunately, the article doesn't say what happens at 400 mg.

MCF-7 are breast cancer cells that grow on estrogen. So what the test does is measure estrogenic effect. That's the same thing we do when we measure growth. So if you already have breast cancer, stay away from phyto-estrogens altogether.

The same test on hops and soy gives the same result: NBE doses make breast cancer cells grow, stalling doses kill them. Yet studies on hops and soy show that in groups of people who take hops or soy in NBE doses, less people get breast cancer.

I haven't seen a similar study on PM yet. Maybe you can find one. This is one of the reasons why I am personally not ready to take PM yet. But if you have any confidence in the crystal ball of an old R&D rat: if the above and similar studies show the same results for PM as for hops and for soy again and again, why would more expensive follow-up studies show results that are dramatically different? Of course, the Thai department of agriculture and export may be reluctant to pay for those studies.

If you take away all the magic that has been created around PM on this forum, the hard scientific facts tell me that PM is just another phyto-estrogen. The difference with hops, soy and flax is in the side effects. And if PM did contain some unknown carcinogen (plants never do), how would that make the Thai cancer statistics look? I bet the Thai department of health would have been on it long ago.

I'll check if I can find a more complex study. But each time I look, what the Thai government has payed for so far is much less than what the Belgian government have done for hops, and the UK government on lignans from grains, and even the more budget constrained Peruvian government on maca.

I do hope other forum members have found something I overlooked. If not, we'll just have to wait for the front line of science to move forward.

[GorgeousBlonde]

Thank you Isabelle

[chrishoney]

I think that there is more research out there, and what I have read indicates that PM has an anti-proliferative effect on multiple breast cancer lines as well some gynecological cancer cell lines. I did come across the report Isabelle quoted which was done 2004. There has been more research by those and other folks in the far east, which unfortunately, is often overlooked by western medicine. Specifically I found a 2005 study that concluded:

These re- sults suggest that phytoestrogens derived from Pue- raria root could be used as a natural alternative to estrogen, offering a lower risk of gynecological cancer when ERT is considered to alleviate the symptoms of menopause. Moreover, the phytoestrogens could be used as a chemopreventive agent in some gy- necological cancers.
http://www.onius.net/downloads/EMM037-02-06.pdf

Another study in 2007 sought to answer Isabelle's question about what happens at concentrations between 1 microgram/ml and 1000 micrograms/ml. They concluded:

the P. mirifica population exhibited cytotoxic effects at concentrations of 100 micrograms/ml and 1000 micrograms/ml.
http://www.jstage.jst.go.jp/article/jrd/54/1/63/_pdf

Also, because they used two types of estrogenic activity assays, they further concluded that simply looking at in vitro analysis (using the MCF-7 assay) may lead one to potentially false conclusions about the effects of PM on in vivo cells. There is other research (cited in their study) that suggests there is a metabolic activation required for many of the compounds in PM that will affect outcomes of different in vivo assays (rat vaginal cell cornification estrogenic activity assay.) The original 2004 study, only looked at plants from one region of Thailand, at limited dosage concentrations, and using an in vitro assay (MCF-7 cell line.)

Another 2007 study demonstrated:

Pretreatment of 1000 mg/(kg BW day) of P. mirifica tuberous powder resulted in decreasing of the virulence of rat tumor development. The mammary tumor tissues exhibited lower profile of ERα and ERβ as well as ERα/ERβ.
http://www.sciencedirect.com/science/art...220700240X

And a further 2008 study revealed:

At P100 and P1000, bone loss was completely prevented both in trabecular bone mineral density and content. The effects of P. mirifica were, as expected, comparable to that in the EE group.
http://www.sciencedirect.com/science/art...2208000297
(Note: EE group above refers treatment with 17-alpha-ethinylestradiol, analogous to routine HRT)

I only did a relatively cursory survey of the 149 hits I got on www.scholar.google.com for the search string: "pueraria mirifica and breast cancer. I would guess that an in depth study of all of those citations (some would be related to the search string but not yield studies such as those above) would probably yield similar conclusions, with the main one being PM in vivo has a protective effect on breast cancer and other sequelae related to menopause.

Just my opinion of course. Hope this helps.

chrishoney