Can organic and transgenic soy be used as a substitute for animal protein by rats?

Abstract

We evaluated the protein quality of organic and transgenic soy fed to rats throughout life. Thirty female Wistar rats were divided into three groups (N = 10): organic soy group (OSG) receiving organic soybased diet, genetically modified soy group (GMSG) receiving transgenic soy-based diet, and a control group (CG) receiving casein-based diet. All animals received water and isocaloric diet (10% protein), ad libitum for 291 days. After this, the weight of GMSG animals (290.9 ± 9.1 g) was significantly lower (P ≤ 0.04) than CG (323.2 ± 7.9 g). The weight of OSG (302.2 ± 8.7 g) was between that of the GMSG and the CG. Protein intake was similar for OSG (308.4 ± 6.8 g) and GMSG (301.5 ± 2.5 g), and significantly lower (P ≤ 0.0005) than the CG (358.4 ± 8.1 g). Growth rate was similar for all groups: OSG (0.80 ± 0.02 g), GMSG (0.81 ± 0.03 g) and CG (0.75 ± 0.02 g). In addition to providing a good protein intake and inducing less weight gain, both types of soy were utilized in a manner similar to that of casein, suggesting that the protein quality of soy is similar to that of the standard protein casein. The groups fed soy-based diet gained less weight, which may be considered to be beneficial for health. We conclude that organic and transgenic soy can be fed throughout life to rats in place of animal protein, because contain high quality protein and do not cause a marked increase in body weight.

Dietary flaxseed supplementation improves endothelial function in the mesenteric arterial bed

“…Water and diets were provided ad libitum; food consumption (g) and body mass (g) were recorded daily. We used the Growth Index (GI) as a criterion for protein quality evaluation (Daleprane, Feijó, & Boaventura, 2009;Soares, Lucas, & Boaventura, 2005).…”

Evaluation of protein quality from genetically modified and organic soybean in two consecutives generations of wistar rats

“…It is important to emphasize that GGF 0 and GGF 1 did not receive the L-cistine supplement, so there would be no interference in protein use for the chow based on this variety of soybean, since it is a genetically modified organism. When working with this same soybean, Soares et al (2005) did not find differences in weight variation for the rats which were up to 291 days old. In the present study, it was observed that when dealing with the growth and development period, supplements become essential.…”

“…The Coefficient of Alimentary Effectiveness (CAE) was determined by taking the weight gain of the test group, after 28 days, in relation to the test group chow consumption, according to Angelis (1995). To prepare the different kinds of chow, both the varieties of soybeans underwent thermal treatment, according to Soares et al (2005), aiming to reduce the antinutritional factors. Chow composition (Table 1) was based on American Institute of Nutrition (AIN) recommendations (Reeves et al, 1993), according to which, all diets had on average 10% protein (1.75% nitrogen) and 363.95 Kcal/100g.…”

“…Approximately 60% of the products processed in the food industry around the world contain ingredients derived from soybean (Soares et al, 2005). The composition of the soybean includes antinutrients that limit its use, such as lectins, oligosaccharides, phytates, saponins and protease inhibitors (Sant'ana et al, 2000;Barcelos et al, 1999;Miura et al, 2001;Monteiro et al, 2004;Vasconcelos et al, 2001).…”

Effects of Transgenic Soybean and Organic Soybean on Rat Penis Morphology during the Aging Process

“…The animals were fed the respective experimental diets for 15 months (455 days). Soares et al (2005).…”