Cancer-Fighters from Foods
by Mary Ann Littell
Who would have thought that a fragrant bowl of pasta
with tomato sauce might be a panacea against cancers
of the prostate, lung, or stomach? Or that a steaming
hot cup of tea would ward off lung, stomach, or esophageal
cancer? Recently studies have pointed to the health
benefits of tomatoes and green tea, among other foods,
as preventives against different forms of cancer,
particularly those of the digestive tract. Is it truth
The American Cancer Society estimates that diet is
a primary factor in one-third of cancer deaths. Evidence
from countless epidemiological studies indicates that
a diet high in fruits and vegetables is associated
with a lower risk of cancer. "I believe foods are
a good place to look for anticancer agents," says
David August, MD, director of surgical oncology at
the Cancer Institute of New Jersey. "They don't have
side effects, are not toxic, and are safe for long-term
Tomatoes have been making news. In February 1999 the
Journal of the National Cancer Institute published
a Harvard-based study about the benefits of lycopene,
a carotenoid found in tomatoes and tomato-based products.
The article, actually a summary of existing literature,
analyzed 72 studies that looked at the relationship
between different cancers and the consumption of tomatoes
and tomato-based foods, particularly cooked products
like spaghetti sauce, tomato paste, and ketchup. In
57 of the 72 studies, tomato consumption was linked
to a reduced risk of cancer, particularly those of
the prostate, lung, and stomach.
Green tea has also had its share of attention. Studies
have suggested it offers numerous health benefits,
including protection against colorectal cancers. August,
who is also an associate professor of surgery at UMDNJ-Robert
Wood Johnson Medical School, has been studying the
effects of green tea on the mucosal lining of the
rectum. Green tea contains polyphenols, a class of
antioxidants found in plants. The polyphenols inhibit
arachidonic acid metabolism, reducing -- among other
things -- the levels of prostaglandin in the rectal
"There is a correlation between prostaglandin levels
and the risk of colorectal cancer," says August. "Nobody
knows why, but the higher the levels of prostaglandin,
the greater the risk." In the United States, colorectal
cancer is the second leading cause of cancer deaths.
It is the third most common cancer in men and the
second most common cancer in women.
August has long been interested in nutrition and its
role in disease prevention. In 1997 he and C.Y. Yang,
PhD, a biochemist at Rutgers University, conducted
a preliminary study on the possible benefits of green
tea in reducing the risk of colorectal cancer. Specimens
were collected from the gastrointestinal tracts of
patients 12 hours after they drank one cup of green
tea. "We found signs of increased levels of polyphenols
in those specimens," said August.
August and Yang recently completed another Phase I/II
study assessing the potential of green tea as a chemopreventive
agent for colorectal cancer. Fifteen patients underwent
rectal biopsies immediately before and after drinking
.6, 1.2, or 1.8 gms. of green tea solids dissolved
in warm water. The biopsies were then tested for prostaglandin
levels. In 71 percent of the patients tested, prostglandin
levels were reduced after drinking the green tea.
Higher doses of tea were no more effective than the
lower dose in reducing prostaglandin.
The green tea research has been funded by Unilever,
which recently established an endowed chair at RWJMS
for the study of nutrition and its role in disease
prevention (see UMDNJ Matters, page 00). Unilever
is the parent company of Lipton Tea. August, who plans
to proceed with a longer-term, Phase II study of green
tea, is a passionate advocate of a healthy diet. His
recommendations go beyond tomatoes and green tea.
"I advise patients to eat a variety of high-fiber
foods in moderation, particularly fruits and vegetables
which are high in beta carotene and lycopene," he
says. "But it's not what many people want to hear.
They say, 'It's not that easy.' Well, it is that easy."
He recommends getting nutrients from foods rather
than supplements. "Supplements are not as effective
as the real thing," he says. "The bioavailability
of certain nutrients is often limited in supplements."
He also points out that interactions between a variety
of food-based substances are not well understood.
For example, lycopene seems to be more readily absorbed
from cooked, rather than raw, tomatoes. The addition
of a small amount of fat (such as the olive oil in
spaghetti sauce) enhances the absorption of the fat-soluble
As interesting (and well-reported) as the tomato study
was, August believes more research on lycopene is
needed before it's called a magic bullet. "The people
in the study ate many other foods in addition to tomatoes,"
he says. "So how can you attribute the lower incidence
of cancer to tomatoes? The next step could be a more
definitive study: for example, one group eating three
tomatoes a day and a second group eating no tomatoes
Reprinted with permission from of HealthState published
by the University of Medicine and Dentistry of New
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