* Risk of cancer cut by 8 pct overall for older men
* Benefit appears higher if prostate cancer excluded
* Landmark study suggests balanced vitamin intake better
than high doses
By Deena Beasley
LOS ANGELES, Oct 17 (Reuters) – Swallowing a daily
multivitamin can reduce the risk of cancer by at least eight
percent in middle-aged and older men and appears to have no
dangerous side-effects, according to the first large-scale,
randomized study on the subject.
The protective effect of the daily pill was described as
“modest” by the trial investigators who emphasized that the
primary use of vitamins was to prevent nutritional deficiencies.
The findings were published in the Journal of the American
Medical Association and presented on Wednesday at a meeting of
the American Association for Cancer Research in Anaheim,
California.
“This is indeed a landmark study,” said Cory Abate-Shen, a
professor of urological oncology at Columbia University Medical
Center who was not involved in the trial. “It suggests that a
balanced multivitamin approach is probably more beneficial than
increasing to high levels any one vitamin.”
About half of U.S. adults take at least one daily dietary
supplement – the most popular being a multivitamin, according to
the U.S. Centers for Disease Control and Prevention.
The U.S. Physicians Health Study II included nearly 50,000
male doctors aged 50 and older and spanned more than 10 years.
Participants were randomly assigned to a multivitamin – Pfizer
Inc’s Centrum Silver – or a placebo. The research was
sponsored by the National Institutes of Health.
Several previous studies, many relying on self-reported use
of specific vitamins or supplements, have generated mixed
results in terms of cancer outcomes.
“There have been some other trials that have tested
combinations, often at high doses, of certain vitamins and
minerals,” said Dr. Howard Sesso, one of the study’s authors and
an associate epidemiologist at Brigham and Women’s Hospital in
Boston. “Our trial took a very commonly used multivitamin that
has basically low levels of all the different essential vitamins
and minerals.”
The findings suggest that the biggest health benefit may
come from a broad combination of dietary supplements, he said.
EFFECT IS GREATER FOR NON-PROSTATE CANCERS
Last year, the questionnaire-based Iowa Women’s Health Study
found that older women who take multivitamins have slightly
increased death rates compared to those who don’t.
A study examining whether vitamin E and selenium could
reduce the risk of prostate cancer was stopped prematurely in
2008 after men taking 400 international units (IU) of the
vitamin showed an increased risk of developing the cancer.
Over-the-counter multivitamins typically contain 15 to 25 IU of
vitamin E.
The newly-released Physicians Health Study showed an 8
percent reduction in total cancer occurrence for participants
taking a multivitamin, but no benefit was seen for rates of
prostate cancer, the most common cancer seen among the
participants in the study.
Excluding prostate cancer, researchers found about a 12
percent reduction in overall cancer occurrence and said the
protective effect seemed to be greater in people who had
previously battled cancer.
They also saw a 12 percent reduction in the risk of death
from cancer, although those findings also were not statistically
significant.
Researchers said they planned to continue to follow the
study group to monitor the effect of vitamin intake over time,
and said additional studies would be needed to see if there were
similar benefits for women or younger men.
“It doesn’t seem like there is any particular risk
associated with taking a vitamin and there might be a small
benefit,” said Dr. David Weinberg, chief of the department of
medicine at Fox Chase Cancer Center in Philadelphia. He was not
involved in the study.
(Reporting By Deena Beasley; Editing by Michele Gershberg and
Paul Simao)
