Effects of voluntary running and soy supplementation on diet-induced metabolic disturbances and inflammation in mice

Authors: Yan, Lin; GRAEF, GEORGE - University Of Nebraska; Larson, Kate; JOHNSON, LUANN - University Of North Dakota

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2013
Publication Date: 9/6/2013
Publication URL: http://handle.nal.usda.gov/10113/58056
Citation: Yan, L., Graef, G.L., Claycombe, K.J., Johnson, L.K. 2013. Effects of voluntary running and soy supplementation on diet-induced metabolic disturbances and inflammation in mice. Journal of Agricultural and Food Chemistry. 61:9373-9379.

Interpretive Summary: The worldwide prevalence of overweight and obesity has been considered a global epidemic. Obesity occurs when there is an imbalance between energy intake and expenditure which leads to excessive accumulation of fat in various adipose tissues and organs. Adipose tissues are considered an endocrine organ which produces a number of adipocytokines that contribute to a state of chronic low grade systemic inflammation and facilitate metabolic disturbance in obesity. Physical activity and dietary modification are two key approaches that may reduce the risk of obesity. The present study investigated the effects of voluntary running and soy protein supplementation on metabolic disturbance and inflammation in high-fat diet-fed mice. The high-fat diet significantly increased whereas running significantly reduced body weight gain and fat mass compared to their respective low-fat and sedentary controls; soy supplementation did not affect either weight gain or fat mass. The high-fat diet significantly increased plasma concentrations of insulin, triglycerides and obesity-contributing adipocytokines. Both running and soy feeding reduced insulin, triglycerides and adipocytokines. These results indicate that both voluntary running and soy protein supplementation down-regulates adipose-mediated inflammation. The difference between them was that the former, but not the latter, was through an action of weight reduction. Soy protein is an ideal substitute for animal protein because of its high protein quality. Further investigations are warranted to the roles of soy protein as a dietary modification in weight management and in reducing the risk of obesity, particularly to those with restricted capability to be physically active.

Technical Abstract: The present study investigated the effects of voluntary running and soy supplementation on diet-induced metabolic disturbance and inflammation in male C57BL/6 mice using a 2x2x2 design in which the effects of diet (AIN93G or its modification with 45% calories from fat), activity level (sedentary or running) and protein source (casein or soy protein isolate (SPI)) and their interactions were assessed. The high-fat diet significantly increased whereas running significantly reduced body weight gain and fat mass compared to their respective AIN93G and sedentary controls; the SPI supplementation did not affect either measurements compared to the casein-based diet. The high-fat diet significantly increased plasma concentrations of insulin, glucose, triglycerides, leptin, monocyte chemotactic protein-1 (MCP-1), plasminogen activator inhibitor-1 (PAI-1) and tumor necrosis factor-a (TNF-a), and running significantly reduced these parameters. The high-fat diet significantly reduced plasma adiponectin concentration while running significantly increased plasma adiponectin. The SPI feeding significantly reduced plasma levels of insulin, glucose, triglycerides, leptin, MCP-1 and TNF-a (but it did not affect PAI-1 and adiponectin); particularly it significantly reduced plasma insulin, MCP-1 and TNF-a in high-fat diet-fed groups. These results indicate that both voluntary running and SPI supplementation down-regulates inflammation in high-fat diet-fed mice. The difference between them was that the former, but not the latter, was through an action of weight reduction. Further investigations are warranted to the roles of soy protein as a dietary modification in weight management and in reducing the risk of obesity, particularly to those with restricted capability to be physically active.