Capsaicin, the component that gives jalapeno
peppers their heat, may also kill prostate cancer cells,
a new study suggests.
Initial experiments in cancer cells and mice show that
capsaicin causes prostate cancer cells to undergo a kind
of suicide. Researchers speculate that, in the future,
pills containing capsaicin might be used as therapy to
prevent prostate cancer's return.
According to their report, capsaicin caused almost 80
percent of prostate cancer cells in the mice to die. In
addition, prostate cancer tumors treated with capsaicin
were about one-fifth the size of tumors in untreated mice.
"Capsaicin inhibits the growth of human prostate
cancer cell in Petri dishes and mice," said lead
researcher Dr. H. Phillip Koeffler, director of hematology
and oncology at Cedars-Sinai Medical Center and a professor
of medicine at the University of California, Los Angeles.
Based on the findings, Koeffler believe the next step
is a trial to see if it works in patients with prostate
cancer.
The report appears in the March 15 issue of Cancer
Research.
Capsaicin probably has several effects, Koeffler said.
Most noticeable is its effect in blocking NF-kappa Beta,
a molecular mechanism that promotes cancer cell growth,
he noted.
In addition, capsaicin also was effective against leukemia,
and might be effective in slowing or preventing the growth
of other cancers as well, he added.
But it's still too early to reach for the chili sauce,
Koeffler said.
"I am not recommending that people increase their
consumption of peppers," he said. "Our calculation
is that you would have to eat 10 habanera peppers three
times a week, which would be equivalent to the amount
of capsaicin we gave to the mice."
The researcher believes capsaicin could someday gain
a place in adjuvant prostate cancer therapy. For example,
it might be used after prostate surgery to kill cancer
cells in patients whose blood PSA levels start to rise,
indicating the presence of tumors too small to be seen,
he said.
The study does highlight the crossover that can occur
between conventional and alternative therapies. "We
should take note of herbal medicines and then use modern-day
techniques to find what the active compounds are and bring
them into clinical trials," Koeffler said.
One expert thinks it's too early to know if capsaicin
will ever be an effective prostate cancer treatment, however.
"Since large amounts of capsaicin have never been
given to people, we don't know what the side effects might
be," cautioned Dr. Len Lichtenfeld, deputy chief
medical officer at the American
Cancer Society. "We don't know about the right
dose or anything."
Lichtenfeld believes that any trial should be done in
patients who are not responsive to other standard therapies.
"We are ways away from a clinical trial," he
said. "We need more basic research before we start
treating patients."
Another expert concurred.
"This study does not prove that capsaicin will prove
effective in the treatment of prostate cancer in humans,"
said Dr. David L. Katz, an associate professor of public
health and director of the Prevention Research Center
at Yale University School of Medicine. "Nor does
it tell us that eating peppers rich in the substance will
help prevent such cancer, or forestall its growth. But
it provides a compelling argument for clinical study of
capsaicin in human prostate cancer to put these questions
to the test."
"This paper should serve to remind us that herbal
remedies and pharmacotherapy are often of common origins,
differing only in our capacity to identify, purify and
package the active ingredients," Katz said. "This
work suggests that the conventional medical community
should turn a discriminating eye, rather than a jaded
eye, toward time-honored herbal treatments. Many will
doubtless prove ineffective when put to the test of high-quality
research. But some will pass that test, and we must meticulously
distinguish between them."
