Effects of low-fat and/or high-fruit-and-vegetable diets on plasma levels of 8-isoprostane-F2alpha in the Nutrition and Breast Health study.

Dietary patterns that involve both a decrease in fat and an increase in fruit and vegetable (FV) intake may decrease cancer risks. In this study, a total of 122 premenopausal women with a family history of breast cancer were randomized into one of four diets for 12 mo: nonintervention, low-fat (15% of energy from fat), high-FV(9 servings/d), and combination low-fat/high-FV Fasting blood samples were obtained at baseline and after 3, 6, and 12 mo. Levels of 8-isoprostane-F2a in plasma were deter-mined by immunoassay kits. Statistical analyses indicated that levels of 8-isoprostane-F2a decreased significantly with time in the low-fat arm, which is the only intervention that resulted in weight loss; there were no significant changes in the other three diet arms. It is unlikely that this is due to changes in levels of blood lipids because there was little change overtime in plasma total cholesterol, high-density lipoprotein,low-density lipoprotein (LDL), or triglyceride levels in any diet arm, although mean LDL did decrease slightly in women who reduced fat intake after adjustment for change in body mass index (BMI). Levels of baseline 8-isoprostane-F2a were significantly higher in obese women than in overweight or normal weight women, and change in BMI was significantly correlated with change in 8-isoprostane-F2a levels. These results indicate that low-fat diets or high-FV diets are unlikely to affect plasma levels of 8-isoprostane-F2a in healthy,premenopausal women who do not lose weight during dietary change.

Improvement of metabolism among obese breast cancer survivors in differing weight loss regimens.

OBJECTIVE: To compare the efficacy of different weight loss regimens on body weight loss and metabolic improvement in breast cancer survivors. RESEARCH METHODS AND PROCEDURES: Forty-eight obese breast cancer survivors were randomly divided into four groups and were followed for 1 year: 1) the Control group (subjects did not receive specific nutrition counseling); 2) the Weight Watchers group (subjects were given free coupons to attend weekly Weight Watchers meetings); 3) the Individualized group (a registered dietitian provided one-on-one nutritional counseling); and 4) the Comprehensive group (subjects received individualized dietary counseling and free coupons for the weekly Weight Watchers meetings). At baseline and 3-, 6-, and 12-month data collection visits, a fasting blood sample was obtained for assays. A three-day dietary record was kept during the week before these visits and dietary intake was analyzed. RESULTS: Subjects in the three intervention groups lost weight (Control: 1.1 +/- 1.7 kg; Weight Watchers: -2.7 +/- 2.1 kg; Individualized: -8.0 +/- 1.9 kg; Comprehensive: -9.5 +/- 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 reductions in blood leptin levels. DISCUSSION: Because insulin resistance and high blood leptin levels are associated with breast cancer, losing weight to improve these parameters may reduce the risk of recurrence. Only subjects in the Comprehensive group showed significant reductions in body weight and fat, energy intake, and leptin levels. For breast cancer survivors, different weight loss strategies should be considered to assist them in losing weight.