THURSDAY, May 29 (HealthDay News) -- Dried tomatoes, anyone?
A study in the June 1 issue of
Cancer Research finds that the
type of tomato product you eat may play a role in whether it
can fight prostate cancer.
Specifically, an organic carbohydrate known as FruHis, which is
produced when tomatoes are dehydrated, could be the secret
ingredient.
But the study only looked at animals and, the authors warned,
FruHis is not ready for the doctor's office or medicine cabinet
just yet.
"This study was conducted in a rat model, and you cannot
possibly draw any conclusions for people," said study author Valeri
Mossine, a research assistant professor of biochemistry at the
University of Missouri. "That's something we need to do next. But
before you enter a study with humans, you have to prove that
something works with animals. If it works, then you go on."
Several studies have pointed to a prostate cancer-fighting
quality in tomatoes, but the exact mechanisms have been
elusive.
In fact, the U.S. Food and Drug Administration laid out evidence
or rather, a lack of it, behind a previous statement the agency had
issued that tomato consumption is not linked to any reduction in
risk of prostate tumors (or ovarian, stomach or pancreatic
malignancies).
The November 2005 statement issued by the FDA contended that,
"there is no credible evidence to support qualified health claims
for lycopene, as a food ingredient, component or food, or as a
dietary supplement, and reduced risk of any of the cancers in the
petition."
But other experts, including the authors of the current study,
are speculating that some other compound in tomatoes might interact
with lycopene to produce the protective effect.
As the study points out, processing of edible plants (heating,
grinding, mixing, drying, etc.) may have an effect on the
nutritional value of the product, largely due to changes that occur
in organic carbohydrates.
And a dietary component to prostate cancer risk and protection
could help explain well-known geographical differences in the
incidence of the disease.
"We were trying to show that a combination of two different
entities in tomato products which appear out of the preparation of
tomato powder might interact together," Mossine said.
For this study, rats were divided into four groups of 20: one
group received a control diet, another group received a diet that
included tomato paste, a third group received a diet including
tomato paste plus additional FruHis, and the final group received
tomato powder alone.
All rats were injected with chemicals to induce prostate
cancer.
Rats fed the tomato paste-plus-FruHis survived the longest, 51
weeks without developing tumors, compared with 50 weeks in the
tomato powder group, 45 weeks in the tomato paste group, and 40
weeks in the control group. The study only lasted 51 weeks, so the
tomato paste plus FruHis group could have even longer survival
times, Mossine noted.
Prostate tumors were found in 10 percent of the animals that had
consumed tomato paste plus FruHis, compared with 30 percent of
animals receiving tomato powder alone, 25 percent receiving tomato
paste alone and 60 percent in the control group.
"Our study shows that one of these carbohydrates that we were
suspecting interacts with lycopene, at least in that model that we
were using," Mossine said.
"This is a very reasonable basic laboratory assessment of this
issue with regard to prostate cancer risk," said Dr. K. Scott
Coffield, a professor of surgery at Texas A & M Health Science
Center College of Medicine and a urologist-oncologist with Scott
& White. "What will be necessary at this point will be some
translational research to take this into a clinical setting."
More information
Visit the
National Cancer Institute for more on prostate
cancer.
