Eating fruits and vegetables in adulthood
probably won't help women reduce their chances of getting breast
cancer, according to the biggest analysis of the question ever
Previous research has suggested that diets high in fruits and
vegetables may protect against other kinds of malignancies, such as
colon cancer, but the results with breast cancer have been less
The new report, based on an analysis of eight studies involving
351,825 women, is the largest to date, said Stephanie Smith-Warner,
a scientist at Harvard's School of Public Health who led the
"Although we did not find an association between fruit and
vegetable consumption and breast cancer risk in our study, higher
fruit and vegetable consumption has been associated with a lower
risk of heart disease and other health conditions and continues to
be an important part of a healthy diet," Smith-Warner said.
Nutritionist Gloria Stables, who directs a National Cancer
Institute program that promotes the eating of at least five fruits
and vegetables a day, also noted that the analysis does not answer
whether a lifelong diet high in fruits and vegetables can prevent
against breast cancer.
"Diets, particularly with breast cancer, are going to make an
effect before adulthood," Stables said.
The findings appear in Wednesday's Journal of the American
Breast cancer will be diagnosed in about 192,000 U.S. women this
year and will kill about 40,600, according to the American Cancer
Society. About one in eight women can expect to get the disease.
Research into whether diet influences the risk stems from
evidence that the disease is less common in countries where the
typical diet is low in fat and high in fruits and vegetables. Also,
many fruits and vegetables contain potential cancer-fighting
substances such as antioxidants.
The studies documented participants' eating habits at the outset
and then counted the number of breast cancer cases diagnosed during
follow-ups of between six and 15 years. A total of 7,377 cases
Women with the highest consumption of fruits and vegetables --4
to 10 servings a day-- had about a 7 percent lower risk than women
with the lowest consumption -- about one to three servings. But the
reduction was not considered statistically significant.
Under U.S. dietary guidelines, one serving equals about one
medium-size piece of fruit or a half-cup of cooked vegetables.
The findings contradict results of a 1997 review by the American
Institute for Cancer Research, which concluded that a diet high in
fruits and especially vegetables probably decreases the risk of
In a JAMA editorial, University of Utah researcher Martha L.
Slattery said the studies in the Harvard analysis did not all
examine the same fruits and vegetables, which "may be especially
problematic if only certain types of vegetables or fruits confer
"In the meantime, an apple (or broccoli stalk) each day is
probably not a bad idea," Slattery said.