SEATTLE, Oct. 9 /PRNewswire/ -- Postmenopausal women who want to
significantly decrease their breast-cancer risk would be wise to exercise
regularly and keep their weight within a normal range for their height,
according to new findings from the Women's Health Initiative to be
published in the journal Obesity.
The multicenter team of researchers, led by Anne McTiernan, M.D.,
Ph.D., of Fred Hutchinson Cancer Research Center, found that women who had
the lowest body-mass index, or BMI, and the highest physical-activity
levels had the lowest levels of circulating estrogens, sex hormones that
can fuel breast- cancer growth.
Specifically, they found a significant decrease in the two most common,
biologically active forms of estrogen, estrone and estradiol, among the
most active, lean women studied. The researchers found that women with high
BMI and low physical-activity had mean estrogen concentrations that were 50
percent to 100 percent higher than that of women with low BMI and high
activity levels.
"Women with high levels of estrogens have a two-to-four-times-higher
risk of breast cancer than women with very low levels," said McTiernan, a
member of the Hutchinson Center's Public Health Sciences Division and
co-investigator of the Women's Health Initiative Clinical Coordinating
Center, which is based at the Center. "If a woman can keep her own natural
estrogens lower after menopause, it is probably going to be beneficial in
terms of reducing her risk of breast cancer."
The study, based on a random sample of 267 postmenopausal women
nationwide selected from the WHI Dietary Modification Trial, is the first
of its kind to examine the dual impact of body weight and physical activity
on levels of various circulating sex hormones thought to impact cancer
risk.
"Other studies have looked at the impact of body weight by itself or
physical activity by itself but this is the first to look at both together
regarding their influence on hormone levels," McTiernan said. "This gives
us a new understanding that combining weight control with high levels of
physical activity is necessary for keeping estrogens at a healthy level in
postmenopausal women." Exercising vigorously for 30 to 60 minutes a day,
five days a week would achieve this benefit, McTiernan said.
BMI is a measure of body fat based on height and weight. The World
Health Organization divides BMI into the following categories for both men
and women: underweight (18.5 or lower), normal (18.5 to 24.9), overweight
(25 to 29.9) and obese (30 or greater). A BMI calculator is available on
the National Institutes of Health Web site at
http://nhlbisupport.com/bmi/bmicalc.htm .
The National Heart, Lung and Blood Institute, U.S. Department of Health
and Human Services, funded the study, which also involved investigators
from Harbor-UCLA Research and Education Institute, Albert Einstein College
of Medicine, University of Pittsburgh, University of Florida, University of
Southern California and Northwestern University.
Note for media only: To obtain an embargoed copy of the paper,
"Relation of body mass index and physical activity to sex hormones in
postmenopausal women," or to arrange an interview, please contact Dean
Forbes, (206) 667-2896 or dforbes@fhcrc.org.
At Fred Hutchinson Cancer Research Center, our interdisciplinary teams
of world-renowned scientists and humanitarians work together to prevent,
diagnose and treat cancer, HIV/AIDS and other diseases. Our researchers,
including three Nobel laureates, bring a relentless pursuit and passion for
health, knowledge and hope to their work and to the world. For more
information, please visit fhcrc.org.
SIDEBAR
SEATTLE-AREA WOMEN NEEDED FOR A DIET AND EXERCISE STUDY
WHAT: Nutrition and Exercise for Women (NEW) Study - A study that
examines the effects of exercise and nutrition on breast-cancer
risk factors.
Fred Hutchinson Cancer Research Center aims to recruit more
than 500 Seattle-area participants for this National Cancer
Institute-funded study, led by Anne McTiernan, M.D., Ph.D., in
the Center's Public Health Sciences Division.
WHO: The study seeks healthy overweight and sedentary postmenopausal
women (ages 50 to 75) who live in the Seattle area and are
willing to travel to the Hutchinson Center for a yearlong
exercise or nutrition intervention.
Eligibility requirements include being a nonsmoker, not using
hormone therapy for the past six months, getting less than an
hour of moderate activity per week, and being above a certain
weight threshold, depending upon height.
Those who qualify must be willing to not participate in any
other exercise or weight-loss programs during the 12-month
study enrollment and must be willing to be randomly (like the
toss of a coin) assigned to one of four following groups:
-- Moderate-intensity aerobic exercise for 45 minutes a day, five
days per week for a year.
-- A reduced-calorie diet for a year.
-- Aerobic exercise and a reduced-calorie diet for a year.
-- No intervention (to serve as a control, or comparison, group).
At the end of the yearlong study, these women will receive a
free, two-month pass to the center's state-of-the-art exercise
facility and get to work out under the supervision of a
personal trainer. They'll also get a chance to attend four
group weight-loss meetings and will receive a variety of
educational handouts about diet and exercise.
WHERE: Fred Hutchinson Cancer Research Center Prevention Studies
Clinic, 1100 Fairview Ave. N., Seattle. Designated parking for
study participants is free of charge.
CONTACT: Women interested in more information may call the NEW Study
information line at (206) 667-6444, e-mail new@fhcrc.org or
visit http://www.thenewstudy.org.
Dean Forbes
(206) 667-2896
dforbes@fhcrc.org
SOURCE Fred Hutchinson Cancer Research Center
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Related links:
http://nhlbisupport.com/
http://www.fhcrc.org/
CONTACT:
Dean Forbes, +1-206-667-2896, or
dforbes@fhcrc.org
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