"What are the Effects of the Hops Phytoestrogen in Beer?"
Hops have been used for centuries
as a flavoring agent in beer,
but over the years a recurring suggestion
has been that hops, and therefore beer
may be estrogenic.
Thanks to a potent phytoestrogen in hops
called 8-PN, also known as hopein.
Might beer drinking affect our hormones?
Now even just the alcohol in beer
can reduce testosterone levels in men,
so when beer was tested as a source of estrogens,
the alcohol was first removed.
They tested the equivalent of one can of beer a day for one month
on the hormone levels of postmenopausal women,
so as to not confound the results
with endogenous estrogens.
And they found significant alterations of hormonal levels
during the beer month,
and then coming back to baseline a week afterwards.
But does this have any clinical effects—
either good or bad?
A cross-sectional study of about 1,700 women
found that beer drinkers appeared to have better bone density;
perhaps because of the pro-estrogenic effects?
They don’t recommend women start drinking beer
for bone health,
but suggest that it may have beneficial bone effects
for women who already drink.
What about helping with hot flashes?
About half of postmenopasal and perimenopausal women
in the U.S. suffer from hot flashes,
whereas the prevalence in Japan
may be ten times lower,
presumed to be because of their soy consumption.
What about hops?
There have been a few studies like this...and this
showing potential benefit, leading to this 2013 review
suggesting that hops extracts may be somewhat effective
in treating menopausal discomforts,
but that was before this study,
which reported extraordinary results
with about a half teaspoon of dried hops flowers.
For example, hot flashes on the bottom,
and the placebo group on the right there,
the women started out having about 23 hot flashes a week
and throughout the three-month study
continued to have 23 hot flashes a week.
In the hops group, they started out even worse,
but then down to 19 at the end of the first month
then nine, then just once a week, basically.
And similar findings were reported
for all the other menopausal symptoms measured.
But hey, animal estrogens work too.
Millions of women used to be on horse hormones,
Premarin, from pregnant mare urine.
That too took care of hot flashes too
and curtailed osteoporosis,
but caused a pesky little side effect
called breast cancer.
Thankfully when this was realized
and millions of women stopped taking it,
breast cancer rates fell in countries around the world—
this is data from California.
The question, then, is are the estrogens in hops
more like the breast cancer promoting horse estrogens,
or the breast cancer preventing soy estrogens?
The key to understanding the health-protective potential
of soy phytoestrogens
is understanding the difference
between the two types of estrogen receptors.
There's alpha receptors and beta receptors.
Unlike animal estrogen, the soy phytoestrogens
bind preferentially to the beta receptors.
And in breast tissue they’re like yin and yang
with the alpha receptors signaling breast cell proliferation,
explaining why horse hormones increase breast cancer risk,
whereas the beta receptors where the soy binds,
opposes that proliferative impact.
So does the hops phytoestrogens prefer beta too?
No. 8-PN is a selective estrogen receptor alpha promoter.
Surprisingly and in clear contrast to the soy,
8-PN is a much weaker binder
of beta than of alpha.
So that explains why hops is such a common ingredient
in so-called breast enhancing supplements,
because it acts more like estrogen estrogen.
Given the breast cancer concerns,
use of such products should be discouraged.
But just drinking beer could provide the exposure
to the hops estrogen as is found in these kinds of products,
which could help explain
why beer may be more carcinogenic
to the breast than some other forms of alcohol.