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.
Fish Oil Does Not Prevent Cancer
A systematic review published in JAMA: The Journal of the American Medical Association shows that fish oil does not prevent cancer. The review analyzed the results of 38 prior studies of the effect of fish oil on the risk of cancers of the breast, colon, lung, prostate, skin, and other sites. Individual study results varied. Some showed increased risk from fish oil, others showed reduced risk, and most showed no effect. The combined result was that fish oil has no evident protective effect against cancer.
MacLean CH, Newberry SJ, Mojica WA, et al. Effects of omega-3 fatty acids on cancer risk: a systematic review. JAMA. 2006;295:403-415.
Obesity Linked to the Return of Prostate Cancer
Men who have been treated for prostate cancer are less likely to have a recurrence if they maintain a healthy weight, according to a recent study in the journal Urology. University of California researchers analyzed data on 2,131 prostate cancer patients from 1989 to 2002, using the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) database.
Obese men, defined as those with a body mass index (BMI) greater than 30, were found to have a 30 percent increased risk of cancer recurrence, compared with those with lower body weights. Very obese patients (BMI greater than 35) had the overall greatest risk of recurrence—about 70 percent higher than thinner men. Results emphasize the importance of maintaining a healthy weight.
Other research has shown that the average person following a vegetarian diet weighs about 10 percent less than the average meat-eater and that low-fat vegetarian diets are effective in helping people achieve and maintain a healthy weight. Furthermore, vegetarians are less likely to develop cancer when compared with their meat-eating counterparts.
Bassett WW, Cooperberg MR, Sadetsky N, et al. Impact of obesity on prostate cancer recurrence after radical prostatectomy: data from CaPSURE. Urology. 2005;66:1060-1065.
The Cancer Project is a nonprofit PCRM subsidiary that advances cancer prevention and survival through nutrition education and research.