April 6, 2010 -- Eating a diet rich in fruits and vegetables is good for
many reasons, but don't expect it to offer much protection against cancer,
according to a new study.
The researchers aren't saying the fruits and vegetables have no effect.
"Fruits and vegetables are likely to be protective, although the effect is not
likely to be large," says study author Paolo Boffetta, MD, MPH, deputy director
of The Tisch Cancer Institute at Mount Sinai School of Medicine in New
But he hastens to add that eating plenty of fruits and vegetables is good
for a number of other reasons, such as reducing the risk of cardiovascular
disease. His study looked at the big picture, he tells WebMD, and so it's still
possible that specific fruits and vegetables, or substances in them, could be
''In the past, there was a strong belief that fruits and vegetables were
strongly protective against cancer," Boffetta says. "In the last 10 or 15 years
there have been a number of studies that did not confirm this
So Boffetta and his colleagues analyzed data from the large EPIC study
(European Prospective Investigation Into Cancer and Nutrition). It included
more than 142,000 men and 335,000 women from 10 Western European countries,
evaluated between 1992 and 2000.
The researchers looked at detailed dietary information and asked about
alcohol intake, smoking, and other lifestyle habits.
After a median follow-up of nearly nine years, Boffetta's team looked at the
association between fruit and vegetables and cancer risk and focused on the
effect of increasing intake.
More than 30,000 participants learned they had cancer during the follow-up
Fruits, Vegetables, and Cancer Risk: Results
The median intake of fruits and vegetables was 335 grams a day, the
equivalent of about two and a quarter apples. "One apple or one fruit is
about 150 grams," Boffetta says.
They looked at the effect of increasing intake. "The more you eat, the more
protective," Boffetta tells WebMD, "but the magnitude of this effect is very
For instance, he says, those who increased their intake by about 200 grams a
day, or about 1.5 servings a day, had a 3% or 4% reduced risk of getting
The effect was weaker for fruits when considered alone than for vegetables,
Boffetta is not certain whether the findings hold for a U.S. population, but
he speculates they probably do.
It's also possible that certain substances in specific fruits or vegetables
may be more protective, Boffetta says. Lycopene, a substance found in tomatoes,
for instance, has been found to reduce prostate cancer risk.
"Our purpose was really to look at the big picture," he says. "It's a little
diluted when you look at the big picture."