(HealthDay News) — In postmenopausal women at increased risk of breast cancer, consumption of a tomato-based diet is associated with increased adiponectin concentration, according to a study published online Dec. 18 in the Journal of Endocrinology & Metabolism.
“Breast cancer risk among postmenopausal women increases as body mass index increases. Practical preventive methods to reduce risk of breast cancer are lacking. Few studies have investigated the effects of carotenoids and isoflavones on circulating adipokines in postmenopausal women,” wrote Adana A. Llanos, PhD, MPH, from The Ohio State University Comprehensive Cancer Center in Columbus, and colleagues.
The researchers examined the effects of lycopene- and isoflavone-rich diets on serum adipokines in a 26-week, two-arm, cross-over trial. Participants included 70 postmenopausal women (mean age, 57.2 years; mean BMI, 30 kg/m²) at increased risk of breast cancer. The interventions included 10-week consumption of a tomato-based or soy-based diet (≥25 mg lycopene or ≥40 g soy protein daily, respectively), with a 2-week washout period in between.
The researchers found that, among all women, adiponectin concentrations increased following the tomato intervention (ratio, 1.09), with a stronger effect in non-obese women (ratio, 1.13). Adiponectin decreased overall following the soy intervention (ratio, 0.91), with a larger reduction seen in non-obese women (ratio, 0.89). Following the interventions, there were no significant changes noted in leptin or in the adiponectin to leptin ratio.
“Increasing dietary consumption of tomato-based foods may beneficially increase serum adiponectin concentrations among postmenopausal women at increased breast cancer risk, especially those who are not obese,” the researchers wrote. “Additional studies are essential to confirm these effects and to elucidate the specific mechanisms that may make phytonutrients found in tomatoes practical as breast cancer chemopreventive agents.”