AUDIO:
COLLEGE STATION – A compound in coffee has been found
to be estrogenic in studies by Texas AgriLife Research
scientists.
Though the studies have not been conducted to determine
recommended consumption amounts, scientists say the compound,
called trigonelline or "trig," may be a factor in
estrogen-dependent breast cancer but beneficial against colon
cancer development.
"The important thing to get from this is that 'trig' has the
ability to act like a hormone," said Dr. Clinton Allred, AgriLife
Research nutrition scientist. "So there is a tie to cancer in the
sense that we are looking at estrogen-dependent cancer cells. But
that doesn't suggest that it would actually cause the disease. I
don't believe there should be any concern about drinking coffee at
this point."
His report was published in the Journal of Nutrition.
Allred's lab studies dietary compounds that can mimic the hormone
estradiol – the primary hormone in women. His main focus has
been to look at how estrogen protects against the development of
colon cancer. Estradiol is one of three estrogen hormones. "There's
a history of these compounds in crops such as soy," Allred said.
"Soy has a number of different compounds that actually can mimic
estradiol in several disease states some of which are good and some
of which have the potential to be more deleterious-type
effects."
Allred said a former colleague mentioned an interest in
finding the properties of "trig" – a natural compound used in
traditional Indian culture for post-menopausal women.
Because the chemical structure of "trig" was so unlike
estradiol, Allred didn't think the compound would be
estrogenic.
"Estrogen-dependent tumors in the presence of estradiol will
grow faster," Allred said. "If you use those cells in a laboratory
setting, you can determine whether something is estrogenic because
they will literally make a tumor grow faster."
He said that a series of experiences and different approaches
showed that "trig," a vitamin derivative, was fairly estrogenic at
very low concentrations.
"We haven't gotten as far as to suggest that if a woman had
the disease that it would necessarily be a problem. But what we've
proven is that the compound is estrogenic or can be at certain
concentrations and doses," Allred said.
He added that "trig" is in coffee beans, though in different
amounts depending on the variety of coffee bean. The two major
types of coffee beans used for what is consumed in the U.S. both
contain it, he said.
"The more you roast a coffee bean, the less there is," Allred
said. "But the most critical aspect is that when you do a water
extract of ground coffee, which is basically how you make a cup of
coffee. It does in fact come out in the water, so we know it is in
a cup of coffee."
Nevertheless, the researchers have no idea what the exposure
level would be or whether a particularly exposure – say from
one cup of coffee – would be in the range seen in the
laboratory tests.
"It is way too early to say that drinking a cup of coffee is
exposing you to something that is definitely going to be
estrogenic. All we know is that there is a compound in there that
can be estrogenic in our systems. That is really the take-home
message," Allred said.
Allred also cautioned that people often narrow one compound
in a food without considering the total mix of compounds and how
they interact with each other or in a human body.
"There is never a single compound when you're looking at
food, and a cup of coffee is a food," Allred said. "There's a whole
bunch of other things in it. There's caffeine. There's actually a
little bit of fat. There are all sorts of others things in a cup of
coffee that could interact with this."
The numerous compounds in each food product means there are
complex interactions, he explained, which is why nutritionists
advise people that the whole food is better than any individual
compound.
"That's why you can't take supplements to make up for food.
You can never take all the things that are in a carrot and replace
a carrot. In the end, you need to eat the carrot," he said. "We're
a long way from understanding what this compound could do in the
context of a food."
He said a concern is that menopausal women seek
over-the-counter phytoestrogen compounds to relieve symptoms such
as hot flashes. Women want what they believe to be a natural and/or
safe mechanism, he said, because hormone replacement therapy has
such a negative connotation.
But, Allred said, researchers estimate that from the time an
estrogen-dependent breast tumor begins until it is diagnosed in a
woman is about 30 years.
"That means there will be a number of women out there who
will become menopausal, and begin to take phytoestrogens in
supplement form," he said. "The majority of those come from soy. So
our concern was, what if a woman becomes menopausal which means her
estrogen levels are going to be low, she has estrogen-dependent
breast cancer and doesn't even know it. And now she's consuming
phytoestrogens.
"Physicians would never recommend you be on hormone
replacement therapy if you had estrogen-dependent cancer. From a
toxicology standpoint, it would that be a bad thing if you were
consuming these phytoestrogens in high enough doses. It could be
really dangerous."
A problem is that people believe that natural or
plant-derived compounds are automatically safe which is not
necessarily always true, he said. Also, consuming a compound in its
pure form as a supplement in high doses may not be healthy.
"If we were getting a hormone from an animal, you wouldn't
see people do that," he said. "The only difference is that this is
a plant-derived compound, so they feel it is safe when that may not
be so."
Yet, Allred added, scientists are finding that at least some
of these compounds are doing positive things to prevent colon
cancer.
"So there's going to be places that it's good – just as
we've seen with estradiol," he noted. "There are going to be some
disease states that it is quite good for and some disease states
that you need to be mindful of."
Still, the compound's potential as a weapon against colon
cancer has the researchers "pretty excited about that."
"We're seeing very interesting information as far as tumor
formation and the ability of phytoestrogens to prevent colon cancer
formation. So any other new, natural phytoestrogen that we are able
to identify and relate to the diet, that would be the model we'd
bring it in to," Allred said of possible future studies on
"trig."
He said a hope would be to develop a drug that could treat
colon tissue without getting into the entire body, thus exploiting
the compound's mechanism to protect again cancer formation without
producing other estrogenic effects.
"It's really important for us to come up with strategies that
we can have the benefits in the colon without the risks associated
with (estrogenic compounds)," Allred said.
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