Soy foods have low glycemic and insulin response indices in normal weight subjects

Abstract

BackgroundFoods with a low glycemic index (GI) may provide a variety of health benefits. The objective of the present study was to measure the GI and insulin index (II) of select soy foods.MethodsThe study was conducted in two parts with low-carbohydrate products being tested separately. In Experiment 1, subjects averaged 23.2 years of age with BMI = 22.0 kg/m2, while subjects in Experiment 2 averaged 23.9 years of age with BMI = 21.6 kg/m2. The reference (glucose) and test foods were served in portions containing 10 g of carbohydrates in Experiment 1 (two test foods) and 25 g of carbohydrates in Experiment 2 (four test foods). Subjects consumed the reference food twice and each test food once. For each test, subjects were instructed to consume a fixed portion of the reference food or test food together with 250 g of water within 12 min. Blood samples were collected before each test and at 15, 30, 45, 60, 90, and 120 min after consumption of reference or test foods to quantify glucose and insulin. Two-hour blood glucose and plasma insulin curves were constructed and areas under the curves were calculated. GI and II values for each subject and test food were calculated.ResultsIn Experiment 1, both low-carbohydrate soy foods were shown to have significantly (P < 0.05) lower GI and II values than the reference food. In Experiment 2, three of the four test foods had significantly (P < 0.05) lower GI and II values than the reference food.ConclusionAll but one of the soy foods tested had a low GI, suggesting that soy foods may be an appropriate part of diets intended to improve control of blood glucose and insulin levels.

Soy sterols in the regulation of thyroid functions, glucose homeostasis and hepatic lipid peroxidation in mice

“…Soy bean and its isoflavones were earlier known to exhibit beneficial effects in correcting the hyperglycemia and preventing diabetic complications (Aboutabl et al, 2002;Ali, Velasquez, Hansen, Mohamed, & Bhathena, 2005;Blair, Henley, & Tabor, 2006;Lee, 2006;McCue et al, 2005;Palanisamy, Viswanathan, & Anuradha, 2008;Velso et al, 2008). The present observations now indicate a similar type of effect with its sterol component, but at a lower concentration.…”

Effects of cake made from whole soy powder on postprandial blood glucose and insulin levels in human subjects

“…Foster-Powell et al (2002) have demonstrated that soy milk and soy itself have a low GI. In addition, Blair et al (2006) have reported that low-carbohydrate soy foods have a low GI and a low II, and that the extract of fermented soy (touchi) shows a low GI and antiglycemic response (Fujita et al 2001). Furthermore, in the case of mixed meal, white rice with added fermented soy (natto), soy flour, or fermented soy paste (miso soup) also show a low GI, Correspondence: Tsuneyuki Oku, PhD, Graduate School of Human Health Science, Siebold University of Nagasaki, 1-1-1 Manabino, Nagayo, Nagasaki, 851-2195 Japan.…”

Gluten Free Bread in a Diet of Celiacs

“…The value of GI is calculated by dividing the area under the glycemic curve obtained after consumption of the product containing 50 g of available carbohydrates by equivalent area measured after eating standard product (usually glucose or white bread) containing the same amount of carbohydrates [94,95]. Consumption of products with low GI (< 55) results in a slow and limited increase of glucose level in blood, while after eating products with high GI (> 70) their digestion and absorption is rapid, which is followed by quick growth in concentration of glucose in serum [96,97,98].…”