Worried About Prostate Cancer?
Tomato-Broccoli Combo Shown to Be Effective
The Tomato Magazine
June 2007
RBANA - A new University of Illinois study shows that tomatoes and broccoli—two
vegetables known for their cancer-fighting qualities—are better at
shrinking prostate tumors when both are part of the daily diet than when
they’re eaten alone.
“When tomatoes and broccoli are eaten together, we see an additive
effect. We think it’s because different bioactive compounds in each
food work on different anti-cancer pathways,” said University of
Illinois food science and human nutrition professor John Erdman.
In a study published in the January 15 issue of Cancer Research, Erdman
and doctoral candidate Kirstie Canene-Adams fed a diet containing 10 percent
tomato powder and 10 percent broccoli powder to laboratory rats that had
been implanted with prostate cancer cells. The powders were made from
whole foods so the effects of eating the entire vegetable could be compared
with
consuming individual parts of them as a nutritional supplement.
Other rats in the study received either tomato or broccoli powder alone;
or a supplemental dose of lycopene, the red pigment in tomatoes thought
to be the effective cancer-preventive agent in tomatoes; or finasteride,
a drug prescribed for men with enlarged prostates. Another group of rats
was castrated.
After 22 weeks, the tumors were weighed. The tomato/broccoli combo outperformed
all other diets in shrinking prostate tumors. Biopsies of tumors were
evaluated at The Ohio State University, confi rming that tumor cells in
the tomato/broccoli-fed rats were not proliferating as rapidly. The only
treatment that approached the tomato/broccoli diet’s level of effectiveness
was castration, said Erdman.
“As nutritionists, it was very exciting to compare this drastic surgery
to diet and see that tumor reduction was similar. Older men with slow-growing
prostate cancer who have chosen watchful waiting over chemotherapy and
radiation should seriously consider altering their diets to include more
tomatoes and broccoli,” said Canene-Adams.
How much tomato and broccoli should a 55-year-old man concerned about
prostate health eat in order to receive these benefits? The scientists
did some conversions.
“To get these effects, men should consume daily 1.4 cups of raw broccoli
and 2.5 cups of fresh tomato, or 1 cup of tomato sauce, or ½ cup
of tomato paste. I think it’s very doable for a man to eat a cup
and a half of broccoli per day or put broccoli on a pizza with ½
cup of tomato paste,” said Canene-Adams.
Erdman said the study showed that eating whole foods is better than consuming
their components. “It’s better to eat tomatoes than to take
a lycopene supplement,” he said. “And cooked tomatoes may
be better than raw tomatoes. Chopping and heating make the cancerfighting
constituents of tomatoes and broccoli more bioavailable.”
“When tomatoes are cooked, for example, the water is removed and
the healthful parts become more concentrated. That doesn’t mean you
should stay away from fresh produce. The lesson here, I think, is to eat
a variety of fruits and vegetables prepared in a variety of ways,”
Canene-Adams added.
Reduced Testosterone Levels
Another recent Erdman study shows that rats fed the tomato carotenoids
phytofluene, lycopene or a diet containing 10 percent tomato powder for
four days had signifi cantly reduced testosterone levels.
“Most prostate cancer is hormone-sensitive, and reducing testosterone
levels may be another way that eating tomatoes reduces prostate cancer
growth,” Erdman said.
Erdman said the tomato/broccoli study was a natural to be carried out
at Illinois because of the pioneering work his colleague Elizabeth Jeffery
has done on the cancer-fi ghting agents found in broccoli and other cruciferous
vegetables. Jeffery has discovered sulfur compounds in broccoli that enhance
certain enzymes in the human body, which then act to degrade carcinogens.
“For 10 years, I’ve been learning how the phytochemicals in
tomatoes affect the progression of prostate cancer. Meanwhile Dr. Jeffery
has been investigating the ways in which the healthful effects of broccoli
are produced. Teaming up to see how these vegetables worked together just
made sense and certainly contributes to our knowledge about dietary treatments
for prostate cancer,” said Erdman.
Editor’s note: Authors of the tomato/broccoli study are
Kirstie Canene-Adams, Brian L. Lindshield, Elizabeth H. Jeffery, and John
W. Erdman Jr. at the University of Illinois and Shihua Wang and Steven
K. Clinton of The Ohio State University. The study was funded by the American
Institute for Cancer Research and the U.S. Department of Agriculture.
The U of I study of the effects of tomato carotenoids on serum testosterone
was published in the December 2006 issue of the Journal of Nutrition.
Authors are Jessica K. Campbell, Chad K. Stroud, Manabu T. Nakamura, Mary
Ann Lila and John W. Erdman Jr. Funding was provided by the National Institutes
of Health’s National Cancer Institute. To contact John Erdman, call:
(217) 333-2527 or (217) 766-2617 (cell); e-mail: jwerdman@uiuc.edu. For
other information, contact: Phyllis Picklesimer, (217) 244-2827; e-mail:
p-pickle@uiuc.edu.
© 2007 Columbia Publishing
>> Return to top
Columbia Publishing & Design | 1-800-900-2452
www.tomatomagazine.com