Flavonoids Linked to Better Breast Cancer Survival by Stephen Daniells
An increased dietary intake of flavonoids may enhance
breast cancer survival by over 30 per cent, suggests a new
epidemiological study from the US.
The study of 1,210 women newly diagnosed with breast cancer
found that individuals with the highest intake of flavones and
isoflavones prior to diagnosis had a 37 and 48 per cent lower risk
of all-cause mortality.
Lead author Brian Fink from the University of North Carolina
states, however, that the results are limited to postmenopausal
women and that larger studies are needed to confirm the
findings.
The study is published in the journal Cancer Epidemiology,
Biomarkers & Prevention.
Flavonoids, a class of antioxidants found in tea, red wine,
soybeans, fruit and vegetables, are the focus of increasing study
since oxidative stress has been linked to an increased risk of
various diseases including cancer, Alzheimer's, and cardiovascular
disease.
The new research used a food frequency questionnaire (FFQ) to
assess dietary intake of different flavonoids for the women, aged
25 to 98, during the 12 months prior to diagnosis with first
primary invasive breast cancer.
The population-based, case-control study by Fink, in
collaboration with researchers from six other institutions,
reported 173 deaths amongst the study population, including 113
from breast cancer.
The researchers report that women who reported the highest
average intake of flavones, isoflavones, and anthocyanidins were
associated with a 37, 48, and 36 per cent reduced risk of all-cause
mortality, with similar results reported for breast cancer
mortality.
"Mortality may be reduced in association with high levels of
dietary flavones and isoflavones among postmenopausal U.S. breast
cancer patients," they concluded.
The study does have several notable limitations, including the
reliance on the FFQ for dietary recall over the course of one year,
which is subject to recall error.
In March, Fink also reported that flavonoid- and lignan-rich
diet was associated with a significant reduction in the risk of
developing breast cancer in postmenopausal women (American Journal
of Epidemiology, Vol. 165, pp. 514-523).
Interest in flavonoids is growing rapidly and a mounting body of
science, including epidemiological, laboratory-based and randomised
clinical trials, continues to report the cancer-fighting potential
of a number of different flavonoids, such as isoflavones,
anthocyanidins and flavonols.
According to Business Insights, the market potential for
flavonoids in the dietetic and nutritional supplement market is in
excess of €670m ($862m) for 2007, with annual increases of 12
per cent.
Over one million women worldwide are diagnosed with breast
cancer every year, with the highest incidences in the US and the
Netherlands. The National Cancer Institute estimates that 13
percent of American women will develop breast cancer during their
lives.
The researchers were affiliated with the University of North
Carolina, University of Toledo, University of South Carolina, Mt.
Sinai School of Medicine, Columbia University, Albert Einstein
School of Medicine, and the National Cancer Institute.
Source: Cancer Epidemiology, Biomarkers & Prevention
November 2007, Volume 16, Number 11, Pages 2285-2292 "Dietary
Flavonoid Intake and Breast Cancer Survival among Women on Long
Island" Authors: B.N. Fink, S.E. Steck, M.S. Wolff, J.A. Britton,
G.C. Kabat, M.M. Gaudet, P.E. Abrahamson, P. Bell, J.C. Schroeder,
S.L. Teitelbaum, A.I. Neugut, and M.D. Gammon
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