Location: Arkansas Children's Nutrition CenterTitle: Feeding soy protein isolate prevents impairment of bone acquisition by western diets as a result of insulin signaling in bone Author
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2011
Publication Date: 4/1/2012
Citation: Zhang, J., Lazarenko, O.P., Badger, T.M., Ronis, M.J., Chen, J. 2012. Feeding soy protein isolate prevents impairment of bone acquisition by western diets as a result of insulin signaling in bone. The FASEB Journal. 26 (Meeting Abstracts):244.4. Interpretive Summary: Consumption of a Western diet (WD), characterized by intake of meat, high-fat dairy products and sweet items, can contribute to obesity and increases the risk of type 2 diabetes. However, how this kind of diet impairs bone development and remodeling has not been well understood. In this study, we demonstrated that WD induced impairment of bone quality, and this effect is compliant with obesity and insulin resistance. Supplementation of soy protein isolates (SPI) could reverse the effects of WD by enhancing insulin sensitivity. Furthermore, SPI normalized non-esterified free fatty acid (NEFA) levels in WD rats sera. These results raised the possibility that insulin signaling is one of the most important endocrine pathways for bone mass accretion. The mechanism of SPI promotes bone growth is partly because SPI ameliorate insulin sensitivity. In conclusion, the effects of SPI diet on metabolism and body composition in WD rats are due to stimulated insulin signaling in bone.
Technical Abstract: Excessive consumption of high fat/high cholesterol “Western” diets during postnatal life results in increased energy intake, development of obesity and systemic insulin resistance. However, how this diet impairs bone development and remodeling is not well understood, and no effective dietary interventional strategy has emerged. In the current study, male rats pair-fed a Western diet (WD) for 7 wks start from post natal day 20 displayed obesity with significantly increased gonadal and abdominal fat mass and body weight compared to control (p<0.05). WD rats had increased in bone marrow adiposity, insulin resistance and impaired glucose tolerance. Supplementation of soy protein isolates (SPI) ameliorated the effects of WD. Inhibition of WD-induced impairment of bone acquisition by SPI was associated with increased undercarboxylated osteocalcin secretion and increased IRS1/Akt insulin signaling in osteoblasts. SPI normalized non-esterified free fatty acid (NEFA) levels in WD rats. These results suggest that the effects of SPI diet on metabolism and body composition in WD rats are due to increased of secretion of active osteocalcin and stimulated insulin signaling in bone