|
Though some studies and anecdotal evidence has suggested a link between diet and breast
cancer, a large study of nurses finds that the consumption of any kind of meat or eggs
does not increase the risk of developing breast cancer. Unlike other studies that rely on
women recalling what they have eaten in the past, this study followed women for 18 years
to study the association between diet and breast cancer. However, the researchers do note
that red meat is linked to a higher risk of other diseases, such as heart disease.
To study the correlation between diet and breast cancer risk, Dr. Michelle D. Holmes of
Harvard Medical School and Brigham and Women's Hospital and colleagues followed 88,647
women for 18 years and assessed their diet at five different intervals. Questionnaires
inquired about specific dietary habits. At the end of the study, the researchers found no
evidence that consuming any kind of meat, including fish, or eggs increased the risk of
developing breast cancer.
Past studies on diet and breast cancer have yielded mixed results. The general
consensus has been that monounsaturated fats, such as canola oil or olive oil, may lower
breast cancer risk while diets high in polyunsaturated fats, such as corn oils, tub
margarine, and saturated fats in meats, have been associated with a higher risk of breast
cancer. However, this latest study seems to contradict the link between meat and breast
cancer risk.
Another food, soy, has also been linked to breast cancer, in a positive way.
Small studies have suggested that a diet rich in soy may reduce the risk of developing
breast cancer (though further research is needed). Researchers are also unsure howsoy
may work to protect against breast cancer risk. In a study published in the July 2002
issue of Cancer Epidemiology Biomarkers & Prevention, Rupert W. Jake of Yu
National Medical Research Council Clinical Trials and Epidemiology Research Unit in
Singapore and colleagues suggested that soy may extend women’s menstrual cycles.
Fewer menstrual cycles over a lifetime have been associated with a reduced risk of breast
cancer. Other research focuses more on the contents of soy. For instance, soy contains
natural chemicals called phytoestrogens, which may work as anti-estrogens against breast
cancer development, similar to the breast cancer prevention drug tamoxifen. The theory is that soy, like the drug tamoxifen,
blocks the hormone estrogen from binding to estrogen receptors in breast cancer cells.
Since some breast cancer cells depend on estrogen for survival, a lack of estrogen starves
these cells, causing them to die.
The link between diet and breast cancer is likely to remain controversial. There is a
much higher incidence of breast cancer in areas with high fat diets (such as the United
States) than areas with low-fat diets (such as Japan). However, researchers have
identified other factors that seem to play a larger role in determining breast cancer risk
(although 80% of women diagnosed with breast cancer have no known risk factors). These factors include:
- Advancing age
- Family history of breast cancer
- Personal history of biopsy revealing pre-cancerous conditions, such as lobular carcinoma
in situ (LCIS)
- Genetic mutations of the BRCA1 or BRCA2 genes
- Early onset of menstruation (before age 12)
- Late menopause (after age 50)
- Not having children, or having children after age 30
- Long-term use of hormone replacement therapy (HRT)
Additional Resources and References
|
