Weight loss improves markers of cancer reoccurrence - Nutrition and Cancer

Nutrition Research Newsletter, March, 2004

Obesity is an epidemic in the United States. Approximately 64.5% of the US adult population is either overweight or obese. Weight loss of even just 5% of original body weight has been shown to improve metabolic profiles and, thus, may reduce chronic disease risks. However, the success rate of weight reduction and weight maintenance programs has been disappointingly low.

Breast cancer is one of the types of cancer that is associated with overweight and obesity in postmenopausal women. Obese postmenopausal women have a greater risk of developing breast cancer; and the prognosis following the onset of breast cancer is poorer in obese women or in women who have gained weight after the diagnosis and treatment of breast cancer, as compared with women with normal body weight. In studies where weight loss management involved a dietitian who gave individual attention to each patient's concerns, the results have been shown to be significantly better than those observed in patients involved in group counseling plus an individualized diet and exercise plan.

Weight loss not only reduces cardiovascular risk, but also improves insulin sensitivity, which is of importance to breast cancer survivors because an elevated fasting insulin level is a predictor for cancer recurrence and survival. Investigators examined the possible beneficial effects of three weight loss regimens on insulin resistance and blood lipid and leptin levels in obese breast cancer survivors. Forty-eight women participated. Inclusion criteria are as follows: being between the ages of 18 yrs to 70 yrs; having a BMI > 30.0 kg/[m.sup.2]; having stage I or stage II breast cancer; having been diagnosed within the past 4 years; having been free of any recurrence; and having had no chemotherapy or radiation in the last 3 months. The subjects were assigned into four research groups by random block design--Control, Weight Watchers, Individualized Counseling, and a Comprehensive group including both weight watchers meetings and individualized counseling. The study lasted 30 months. Results of blood samples that were obtained in the first 12 months are reported in the current study.

Subjects in the three intervention groups lost weight (Control: 1.1 kg [ or -] 1.7 kg; Weight Watchers: -2.7 kg [ or -] 2.1 kg; Individualized: -8.0 kg [ or -] 1.9 kg; Comprehensive: -9.7 kg [ or -] 2.7 kg) and percentage body fat, but only the individualized and comprehensive groups had significant losses. Subjects in the comprehensive group showed the most improvement in cholesterol levels and had reduction in blood leptin levels. It appears that a comprehensive intervention, including support groups and individualized counseling, is the most effective treatment for obesity in breast cancer survivors.

K. Jen, Z. Djuric, N. DiLaura, et al. Improvement of metabolism among obese breast cancer survivors in differing weight loss regimens. Obesity Research 12:306-312 (February, 2004) [Correspondence: K. Catherine Jen, Department of Nutrition and Food Science, 3009 Science Hall Wayne State University, Detroit, MI 48202. E-mail: Cjen@sun.science.wayne.edu]