Soya protein- and casein-based nutritionally complete diets fed during gestation and lactation differ in effects on characteristics of the metabolic syndrome in male offspring of Wistar rats

Abstract

The AIN-93G diets based on soya protein or casein were fed to pregnant Wistar rats from day 3 of gestation and compared for their effects on characteristics of the metabolic syndrome in male offspring. Pregnant rats were randomised to either a casein (C) or soya protein (S) diet (n 12) during gestation only (Expt 1) or during gestation and lactation (Expt 2). Male offspring were weaned to either a C or S diet for 9 weeks (Expt 1) or 15 weeks (Expt 2). In Expt 1, pups born to S-fed dams had higher fasting blood glucose (BG), systolic blood pressure (SBP) and diastolic blood pressure (DBP) at week 4, higher blood glucose (BG) response to a glucose administration (P,0·001) and higher body weight (BW) at week 8 (P, 0·05). In Expt 2, consumption of the S diet throughout gestation and lactation resulted in higher BW (P,0·05), DBP (P,0·005) and SBP (P,0·005) in the offspring. They also had higher homeostasis model assessment of insulin resistance (HOMA-IR; P, 0·05) and plasma homocysteine (P,0·05) at weaning, higher fasting BG and glucose response to glucose administration (P,0·005) at week 12 and higher HOMA-IR (P,0·01) at week 15. Although composition of the weaning diets interacted with the diet of the dams, the latter was the dominant factor in determining metabolic outcomes in the offspring. In conclusion, the S diet, compared with the C diet, when consumed during gestation or throughout gestation and lactation increased the presence of characteristics of the metabolic syndrome in the offspring.

Comparison of endpoints relevant to toxicity assessments in 3 generations of CD-1 mice fed irradiated natural and purified ingredient diets with varying soy protein and isoflavone contents

“…F 0 animals fed these diets only during the post-weaning period did not show significant differences in body weights from the natural ingredient diets or from the AIN-93 group, indicating that the diet consumed by the dam during gestation and lactation influenced the pup body weights. The importance of the diet consumed by the dam on pup body weight throughout life has been reported in other studies of soy- versus casein-containing diets, although inconsistent effects have been found, with the soy-consuming F 1 CD-1 mice having lower body weights (Cederroth et al, 2007; Ruhlen et al, 2008) and Wistar rats having higher body weights (Jahan-Mihan et al, 2011; Jahan-Mihan et al, 2012). A study in Sprague-Dawley rats reported no differences in adult body weight between rats fed purified diets with either casein or soy protein isolate as the protein sources (Badger et al, 2001).…”

“…Developmental exposure of Wistar rats to soy protein-containing diet was reported to increase body weight of both male and female rats as adults compared to those fed a casein diet, but glucose intolerance was more pronounced in adult males (Jahan-Mihan et al, 2011). The effects of the dietary protein difference were largely attributed to the dams’ diet during pregnancy (Jahan-Mihan et al, 2012). The data regarding soy diet effects on body weight and obesity are thus somewhat difficult to interpret and may depend on species and strain, the specific soy preparations or components examined, or other diet constituents or properties (e.g.…”

The effect of characteristics of proteins fed during gestation and lactation on development of metabolic syndrome in dams and male offspring of Wistar rats

“…Food intake was also higher in offspring born to dams fed soy protein diet in PW period . These data indicate that even in a nutritionally balanced diet fed during gestation and lactation, the source of protein can influence the risk of MS in the offspring .…”

“…Rats were fasted overnight for 12 h. Blood samples were drawn from the tail vein at fasting and at 15, 30 and 60 min after a glucose administration (0.375 g glucose per mL, 5 g glucose per kg BW) .…”

“…Both high‐protein and low‐protein maternal diets showed detrimental effects on body weight (BW), blood pressure, and metabolic and food intake regulatory systems in the offspring . We have previously reported that pups born to dams fed a soy protein‐based diet had higher BW, systolic blood pressure (SBP) and diastolic blood pressure (DBP) and plasma insulin at week 14 post‐weaning (PW) compared with those born to dams fed a casein‐based diet . Food intake was also higher in offspring born to dams fed soy protein diet in PW period .…”