Beer Phytoestrogens

The Most Potent Phytoestrogen is in Beer

Image Credit: Quinn Dombrowski / Flickr. This image has been modified.

Why do alcoholic men develop so-called man boobs and other feminine traits? We know estrogens produce feminization, and our liver clears estrogens from the body. As such, the original theory was that alcohol-induced liver damage led to the retention of excess estrogens. The problem was that when researchers measured estrogen levels, they weren’t elevated. What’s more, even those with cirrhosis of the liver appeared to clear estrogens from the body normally, and men’s testicles started shrinking even before serious liver disease developed.

So, alternative explanations were considered. If it’s not due to estrogens produced endogenously, meaning within the body, maybe alcoholics are being exposed to “exogenous estrogenic substances from dietary sources”—perhaps from phytoestrogens in the plants that alcoholic beverages are made from. The discovery that plants could contain hormonal compounds was made back in 1951 by two Australian chemists charged with finding out the cause of an “epidemic of infertility in sheep that was ravaging their nation’s wool industry.” It took them ten years, but they finally figured out the cause: a compound called genistein, present in a type of clover, and the same phytoestrogen found in soybeans.

You can read about the dreaded clover disease on scare-mongering websites, but you’ll note they never talk about the difference in dose. To get as much as the sheep were getting from clover, you’d have to drink more than 1,000 cartons of soymilk a day or eat more than 8,000 soy burgers or about 800 pounds of tofu a day.

This is not to say you can’t overdo it. There are two case reports in the medical literature that describe feminizing effects associated with eating as few as 14 to 20 servings of soy foods a day. But at reasonable doses, or even considerably higher than the one or two servings a day Asian men eat, soy phytoestrogens do not exert feminizing effects on men.

So, back in 1951, we realized plant compounds could be estrogenic. Two German researchers realized that perhaps that’s why women who handle hops start menstruating, and, indeed, they found estrogenic activity in hops, which is the bittering agent used to make beer. They found trace amounts of the soy phytoestrogens, but in such tiny quantities that beer would not be expected to have an estrogenic effect. In 1999, however, a potent phytoestrogen called 8-prenylnaringenin was discovered in hops, which I discuss in my video The Most Potent Phytoestrogen Is in Beer. In fact, it’s the most potent phytoestrogen found to date, fifty times more potent than the genistein in soy, “provid[ing] an obvious explanation for the menstrual disturbances in female hop workers in the past.” Today, we have machines to pick our hops, so our only exposure is likely via beer consumption, but the levels in beer were found to be so low that they shouldn’t cause any concern.

Then in 2001, a study on a hops-containing “dietary supplement for breast enhancement” raised the concern that another phytoestrogen in hops called isoxanthohumol might be biotransformed by our liver into the more potent 8-PN, which would greatly augment the estrogenic effect of hops. This study was conducted on mice, though. Thankfully, a study using human estrogen receptors found no such liver transformation, so all seemed fine…until 2005. “[T] he liver is not the only transformation site inside the human body.” The human colon contains trillions of microorganisms with enormous metabolic potential. It’s like a whole separate organ within our body, with a hundred livers’ worth of metabolizing power. So, let’s effectively mix some beer with some poop and see what happens.

Indeed, up to a 90 percent conversion was achieved. Up to then, “the concentration of 8-PN in beer was considered too low to affect human health. However, these results show that the activity of the intestinal microbial community could more than 10-fold increase the exposure concentration.” This can explain why you can detect 8-PN in the urine of beer-drinkers for days: Their gut bacteria keep churning it out. Obviously, the amount of straight 8-PN in beer is not the only source of estrogen effects given this conversion. So, a decade ago, the question remained: Might drinking too much beer cause estrogenic effects and feminize men? See my video What Are the Effects of the Hops Phytoestrogen in Beer? for the update.


Neu entdeckte Substanz hemmt Wachstum von Krebsgeschwulsten

Einer der Rädelsführer beim ungehemmten Wachstum von Krebszellen ist ein Eiweißstoff namens “Myc”. Innsbrucker Forscher haben nun in einem internationalen Team bei einer groß angelegten “Suchaktion” eine neue Substanz gefunden, die seine Aktivitäten stört und damit das Tumorwachstum im Maus-Modell stoppt. Die Studie wurde aktuell in der Fachzeitschrift “PNAS” veröffentlicht.

Myc reguliert in gesunden Zellen, wie oft wachstumsfördernde und -hemmende Gene vom Erbgut abgelesen werden. Bei fast allen Krebsarten beim Menschen ist seine Aktivität erhöht, was das Wachstum und die Vermehrung der Tumorzellen beschleunigt. Darum werden große Anstrengungen unternommen, um Myc in Krebszellen zu hemmen, erklärte Klaus Bister vom Institut für Biochemie der Universität Innsbruck im Gespräch mit der APA.

Vielversprechende Substanz gefunden

Die Forscher unter der Leitung von Peter Vogt und Kim Janda vom Scripps Research Institute in Kalifornien (USA) suchten Substanzen, die verhindern, dass Myc mit seinem Partner “Max” zusammenkommt, um gemeinsam an festgelegte Stellen im Erbgut anzudocken und bestimmte Zielgene zu aktivieren. Unter Hunderten Substanzen, die in einer “Molekül-Bibliothek” zur Verfügung standen, fanden sie vier, die die Bindung von Myc, Max und der Ziel-DNA störten. Die vielversprechendste namens “KJ-Pyr-9″ untersuchten sie genauer.

Stoppt Verbindung mit gefährlichem Eiweißstoff

Dabei fanden sie heraus, dass KJ-Pyr-9 tatsächlich die “Myc-Max-Liaison” behindert und die Zielgene bei Zugabe dieser Substanz nicht länger hoch-reguliert waren. Sie konnte auch verhindern, dass tierische Zellen im Laborexperiment durch gesteigerte Myc-Aktivität zu Krebszellen transformiert wurden.

Tumorzellen hörten auf zu wachsen

Schließlich gelang es ihnen, mit KJ-Pyr-9 das Wachstum menschlicher Tumorzellen zu stoppen: Krebsgeschwulste, die in Mäusen nach der Injektion von menschlichen Brustkrebszellen wucherten, hörten am achten Tag der Behandlung mit KJ-Pyr-9 auf zu wachsen.

Source: VOL.AT