Effects of long-term cranberry supplementation on endocrine pancreas in aging rats.

The effects of long-term cranberry consumption on age-related changes in endocrine pancreas are not fully understood. Here we treated male Fischer 344 rats with either 2% whole cranberry powder supplemented or normal rodent chow from 6 to 22 month old. Both groups displayed an age-related decline in basal plasma insulin concentrations, but this age-related decline was delayed by cranberry. Cranberry supplementation led to increased ß-cell glucose responsiveness during the oral glucose tolerance test. Portal insulin concentration was 7.6-fold higher in rats fed cranberry, coupled with improved ß-cell function. However, insulin resistance values were similar in both groups. Total ß-cell mass and expression of pancreatic and duodenal homeobox 1 and insulin within islets were significantly enhanced in rats fed cranberry relative to controls. Furthermore, cranberry increased insulin release of an insulin-producing ß-cell line, revealing its insulinotropic effect. These findings suggest that cranberry is of particular benefit to ß-cell function in normal aging rats.

High-dose isoflavones do not improve metabolic and inflammatory parameters in androgen-deprived men with prostate cancer.

The profound hypogonadism that occurs with androgen deprivation therapy (ADT) for prostate cancer (PCa) results in complications such as diabetes and metabolic syndrome that predispose to cardiovascular disease. Because phytoestrogens have been associated with an improvement in metabolic parameters, we evaluated their role in men undergoing ADT. Our objective was to evaluate the effects of high-dose isoflavones on metabolic and inflammatory parameters in men undergoing ADT. This was a randomized, double-blind, placebo-controlled, 12-week pilot study. Participants were randomly assigned to receive 20 g of soy protein containing 160 mg of total isoflavones vs taste-matched placebo (20 g whole milk protein). The study was conducted at a tertiary care center in the United States. Thirty-three men (isoflavones = 17, placebo = 16) undergoing ADT for PCa completed this pilot study. Mean age in the 2 groups was 69 years and the majority of men were Caucasians. Mean duration of ADT in both groups was approximately 2 years (P = .70). The 2 groups were well matched at baseline. After 12 weeks of intervention, there was no significant difference in either metabolic or inflammatory parameters between the 2 groups. We found that high-dose isoflavones over a course of 12 weeks do not improve metabolic or inflammatory parameters in androgen-deprived men.