Diet, Exercise and Reduced Stress Slow Prostate Cancer,
Research on 93 Patients Is Direct Evidence That Lifestyle
Changes Can Improve Scores on Blood Test; More Studies Called For
By Rob Stein
Washington Post Staff Writer
August 11, 2005
Eating better, exercising regularly and cutting stress
apparently can slow the progression of early prostate cancer, according to the
first study to provide direct evidence that lifestyle changes can fight the
The study of 93 prostate cancer patients found that those
who adopted a series of lifestyle changes that included a primarily vegan diet,
regular moderate exercise, and yoga and other relaxation techniques scored
better on a standard blood test used to monitor prostate cancer growth a year
later. They were also less likely to require additional treatment, and their
blood showed signs of being able to inhibit prostate cancer cells in lab
Many studies have suggested that adopting healthful
lifestyles can have a host of health benefits, including reducing the risk for
various cancers. But the new research is the latest in a series of recent
studies that have found that actors such as diet, exercise and stress reduction
may have a powerful effect on cancer patients' prognoses.
"Diet and other lifestyle changes play an important role
in the development of many health problems," said Dean Ornish of the University
of California at San Francisco, who led the new study, being published in next
month's issue of the Journal of Urology. "Now we have evidence it can slow the
progression of prostate cancer."
Other researchers said many more studies will be needed to
explore which components of the lifestyle changes may be important, and to
demonstrate whether the effects translate into a reduced risk of dying.
"There's a building body of evidence that lifestyle may
affect cancer progression," said Peter Greenwald of the National Cancer
Institute. "This is a very important area, and this is one more important lead
that indicates a crucial direction for more research."
But given that a healthful diet and regular exercise can
have other benefits, several researchers said there is no reason patients
should not consider adopting them in addition to their standard care.
"The take-home message is that an active lifestyle
combined with a healthy diet definitely decreases the risk of many types of
cancer, and in the case of early nonaggressive prostate cancer, it may slow
disease progression," said Durado Brooks of the American Cancer Society.
Prostate cancer strikes 232,000 American men each year and
kills about 30,000, making it the leading cause of cancer among men and the
second-leading male cancer killer, after lung cancer.
Ornish and his colleagues studied 93 men who had been
diagnosed with early prostate cancer. The men had opted not to seek treatment
immediately but, instead, to closely monitor their tumors.
Half the men adopted a regimen that included a vegan diet
-- primarily fruits, vegetables, whole grains and legumes but no meat, eggs or
dairy products -- supplemented with soy, vitamins and minerals.
That same group of men also started moderate aerobic
exercise, such as walking 30 minutes six days a week; participated in a
one-hour support group meeting once a week; and began using stress-management
techniques, such as yoga, breathing exercises and meditation for an hour a
When the study began and then a year later, the
researchers gave both groups of men the prostate-specific antigen (PSA) blood
test, which is widely used to monitor the progression of the cancer. Those on
the diet and exercise regimen saw their PSA levels drop by an average of 4
percent, while those in the other group saw theirs rise an average of 6
percent, the researchers found.
In addition, blood from the men in the diet and exercise
group appeared to inhibit prostate cancer cells in laboratory tests, indicating
that something in their diet or their bodies' response to the regimen was
inhibiting their cancer, Ornish said.
Moreover, none of those who made the lifestyle changes
needed any cancer treatment during the study period, whereas six of those in
the other group did.
"This is the first randomized trial showing that the
progression of prostate cancer can be stopped or perhaps even reversed by
changing diet and lifestyle alone," said Ornish, who stressed that the changes
should be considered only as an addition to standard treatment and not a
Two recent studies found that breast cancer patients who
ate low-fat diets and exercised regularly were less likely to suffer
recurrences, Ornish noted. "We think we may be able to give many people new
hope and new choices that they didn't have before," he said.
Other researchers were cautious, saying the study had not
yet demonstrated that the lifestyle changes help people live longer, and it was
difficult to pinpoint which aspects of the regimen might be beneficial.
"So many variables were changed in the experimental group
that it is not possible to sort out which of the many lifestyle factors . . .
or combination thereof, was responsible for the observed effects," Howard L.
Parnes of the National Cancer Institute wrote in an e-mail.
In addition, the changes were so dramatic that it is
unclear how many men could sustain them, Parnes said. "Although the findings
appear to support the hypothesis that dietary and lifestyle factors can
potentially alter the natural history of prostate cancer, there are many
In comments accompanying the article, Paul H. Lange of the
University of Washington said the study would likely trigger follow-up
"Even if scientific evidence is still meager,
complementary medicine approaches have strong appeal in practicing the medical
art since they give the patient an active role in his care and promote an
attitude of optimism and hope," he wrote.
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