Abstract and Introduction
Diet and exercise interventions resulted in better maintenance of functional status and reductions in levels of hormones associated with postmenopausal breast cancer.
Obesity has many detrimental health implications, including excess risk for postmenopausal breast cancer and functional decline in cancer survivors. Lifestyle interventions with diet and exercise to reduce weight have been shown to lower risk for cancer and cancer recurrence and to decrease functional decline in older cancer survivors. However, the reproducibility, durability, and real-life adoption of such interventions have been questioned. Two studies address these concerns.
In the initial Reach Out to Enhance Wellness (RENEW) study, investigators assessed the effectiveness of a diet and exercise intervention in 641 sedentary, overweight patients (age, >65; body mass index, 25–40) who were long-term (≥5-year) survivors of breast, prostate, or colorectal cancer (JAMA 2009; 301:1883). They found that those who participated in the 1-year telephone-based intervention achieved favorable changes in physical activity and dietary behaviors, modest weight loss, and less decline in functional status compared with wait-listed controls.
Now, the RENEW investigators update results for the original participants at 2 years (1 year after intervention ended) and report outcomes for controls who participated in the intervention for 1 year after a 1-year delay. In the original intervention group, no significant relapse in diet quality, body-mass index (BMI), or physical activity occurred, although an increase in functional decline was noted. In the delayed-intervention group, improvements in all endpoints were observed, similar to those achieved by the original intervention group. These data speak to the durability of this intervention and the ability of participants to adopt these lifestyle changes after the intervention ends.
In the Nutrition and Exercise for Women (NEW) trial, researchers evaluated the effect of diet and exercise interventions on 439 sedentary, overweight, postmenopausal women (mean age, 58; mean BMI, 30.9). Patients were randomized to a reduced-calorie diet, moderate to vigorous aerobic exercise, combined diet and exercise, or no diet or exercise intervention (controls). The objective was to determine whether the interventions could modify sex hormones that are linked to the risk for developing postmenopausal breast cancer.
Weight loss achieved by a reduced-calorie diet with or without exercise produced significant reductions in serum concentrations of estrone (the primary endpoint), estradiol, free estradiol, and free testosterone, while increasing sex hormone–binding globulin concentrations. Androstenedione concentrations were similar among patients in the intervention groups and controls.
Journal Watch © 2012 Massachusetts Medical Society