GUANGZHOU, China—Similar to the findings of a Japanese study published in The Journal of Nutrition, results from a recent Chinese six-month, randomized controlled trial revealed soy protein with or without isoflavone supplementation did not have favorable effects on glycemic control and insulin sensitivity among postmenopausal Chinese women (Am J Clin Nutr. 2010; DOI:10.3945/ajcn.2009.28813). The randomized, double blind, placebo-controlled trial included 180 postmenopausal Hong Kong Chinese women with pre-diabetes or early untreated diabetes. After a two-week adaptation period, participants were randomly assigned to one of three arms to receive 15 g/d of soy protein and 100 mg/d of isoflavones, 15 g/d of milk protein and 100 mg/d of isoflavones, or 15 g/d of milk protein for six months.
Three- or six-month treatments with soy protein with or without isoflavone supplementation did not result in favorable changes in the descriptors for glycemic control and insulin resistance, namely fasting and two-hour postload glucose, fasting and postload insulin, glycated serum protein, and homeostasis model.
