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Western Diet Partly to Blame for Korea’s Increasing Breast Cancer Rates
Korean women have historically had one of the lowest breast cancer rates in the world, in part because of their traditionally low-fat diet full of fresh vegetables, rice, soybeans, seaweed, and other sea vegetables. However, as they stray from this diet toward a higher fat Western regimen, rates of obesity and breast cancer are catching up with those in Western countries. Researchers in Seoul, Korea, analyzed lifestyle characteristics of 5,000 breast cancer patients admitted to the Asan Medical Center for breast surgery between 1989 and 2004. They found that breast cancer rates among Korean women are increasing faster than the world average. Researchers blame an increase in risk factors, including the consumption of higher fat foods, which, according to the Korean Breast Cancer Society, increased significantly between 1996 and 2000. Other changes that reflect lifestyles of Westernized nations include earlier menarche (perhaps due to diet changes), a delay in childbearing, insufficient breastfeeding, late menopause, and obesity.
Son BH, Kwak BS, Kim JK, et al. Changing patterns in the clinical characteristics of Korean patients with breast cancer during the last 15 years. Arch Surg. 2006 Feb;141(2):155-160.
Low-Fat Diet Improves Breast Cancer Survival
A new report concludes that breast cancer survivors may reduce the risk of recurrence by following a low-fat diet. A National Cancer Institute study followed 2,437 post-menopausal breast cancer patients for five years after standard surgery and cancer treatments. Researchers instructed 1,462 of the patients to continue their regular diets, while 975 patients were given intensive counseling with a dietitian to reduce their fat intake. The control group consumed an average of 51.3 grams of fat per day, which is still lower than the average American’s fat intake. The low-fat group averaged 33.3 grams per day—slightly more than in a typical vegetarian diet. After five years, 12.4 percent of the women eating their usual diet had cancer recurrences, compared with only 9.8 percent of the low-fat diet group: that’s a 24 percent reduction in recurrence. Low-fat dieters with estrogen-negative tumors experienced a 42 percent reduction in recurrence.
Chlebowski RT. Dietary fat reduction in postmenopausal women with primary breast cancer: Phase III Women’s Intervention Nutrition Study (WINS). Paper presented at: American Society of Clinical Oncology Annual Meeting; May 16, 2005; Torrance, CA.
Breast Cancer Again Linked to Animal Fat
Intake of animal fat, especially from red meat and high-fat dairy products, during premenopausal years is associated with an increased risk of breast cancer, according to a report in the Journal of the National Cancer Institute. Harvard researchers conducted a prospective analysis of 90,655 premenopausal women aged 26 to 46 enrolled in the Nurses’ Health Study II using food-frequency questionnaires. Because an increased risk was not associated with eating vegetable fats, researchers hypothesize that other components of meat, such as hormones or carcinogens that develop during cooking, may be to blame.
Cho E, Spiegelman D, Hunter DJ, et al. Premenopausal fat intake and risk of breast cancer. J Natl Cancer Inst. 2003;95:1079-85.
Hormone Replacement Therapy
Hormone Replacement Therapy Is Only a Temporary Fix
Hormone “replacement” increases cancer risk, but is sometimes prescribed to treat hot flashes. However, these symptoms are likely to return as soon as the treatment is stopped, according to a new report from the Women’s Health Initiative. In May 2002, investigators stopped prescribing the hormones when serious risks of breast cancer, cardiovascular disease, stroke, and dementia were found. The 8,405 women who discontinued estrogens and progesterone were then surveyed. More than half of the women who had had hot flashes prior to beginning hormone therapy suffered recurrences when the treatment was ended. Women who had not had hot flashes prior to starting the hormones tended to remain symptom-free after discontinuing them. The study suggests that hormones are not a long-term solution to hot flashes and supports the use of non-hormonal strategies for dealing with menopausal symptoms.
Ockene JK, Barad DH, Cochrane BB, et al. Symptom experience after discontinuing use of estrogen plus progestin. JAMA. 2005;294:183-93.
Broccoli Compound Helps Stop Breast Cancer Cell Growth?
Sulforaphane, a plant compound found in broccoli, cauliflower, Brussels sprouts, cabbage, kale, collard greens and other cruciferous vegetables, has been shown to stop the growth of human breast cancer cells in a study conducted at the University of Illinois. In this study, cancerous mammary cells were exposed to increasing dosages of sulforaphane over a 48-hour period. Within hours, cell division was blocked. The reason: sulforaphane disrupts microtubules, cell components necessary for separating duplicated chromosomes during cell division. The reproduction of the cancer cells was inhibited in a dose-dependent manner, meaning the more sulforaphane the cells were exposed to, the stronger the brake put on cell growth. But, even at low doses, DNA synthesis in both estrogen receptor positive (ER+) and estrogen receptor negative (ER-) cells was significantly inhibited.
Sulforaphane has been found to have cancer preventive properties in previous studies by inhibiting cancer initiation, and this study demonstrates that it may also affect breast cancer promotion and progression.
Jackson SJ, Singletary KW. Sulforaphaneforaphane inhibits human mcf-7 mammary cancer cell mitotic progression and tubulin polymerization. J Nutr. 2004 Sep;134(9):2229-36.Source: Journal of Nutrition