New Study Suggests Soy Protein May Support Colon Health

Results of this study showed that mice fed the soy protein versus casein based diets had significantly reduced body fat, blood insulin levels, fat cell size and expression of genes associated with abnormal colonic cell growth.

8 Oct 2012 --- While much research on soy protein has focused on its cholesterol lowering properties, exciting recent research suggests that consuming soy protein may have benefit in weight management, liver and colon health, which are of specific concern for obese individuals. A new study to be published in PLOS One in September 2012 was conducted in mice and aimed to explore the effects of dietary soy protein or casein on serum hormones implicated in colon health and body fat deposition. The authors had previously shown that inclusion of soy protein in the diets of mice resulted in lower body fat and promoted normal cell growth in the colons of rats.

Results of this study showed that mice fed the soy protein versus casein based diets had significantly reduced body fat, blood insulin levels, fat cell size and expression of genes associated with abnormal colonic cell growth. There was also a trend for lower fat accumulation in the livers of normal mice fed a high fat diet containing soy protein compared to a high fat diet containing casein.

The research led by Dr. Frank A. Simmen in collaboration with Dr. Rosalia C.M. Simmen and their lab groups also gleaned some insights into the possible way that soy protein consumption leads to these benefits by comparing the normal mice fed a high fat diet containing soy protein to a naturally occurring strain of mice that do not express an enzyme important for fat accumulation in the body. These mice are healthy and tend to be smaller and have less body fat than mice without this mutation.  Since soy protein had less of an effect in these mice, it suggests that the gene that is mutated may be in a pathway that is affected when normal mice consume soy protein.

“Our findings support an increasing body of evidence linking healthy diets with altered metabolic states and biomarkers potentially favorable for prevention of chronic diseases” said Frank Simmen, professor in the Department of  Physiology and Biophysics at the University of Arkansas for Medical Sciences in Little Rock.
“We are excited by these findings as they continue to support and extend the observations of other researchers that have shown a benefit of soy protein in maintaining healthy fat levels in the livers of other animal models,” commented Elaine Krul, Science Fellow and Lead, Nutrition Discovery at Solae LLC. “We are eager to confirm these observations in human studies.”

The study was funded by the National Institutes of Health and the Arkansas Biosciences Institute-Arkansas Children's Hospital Research Institute and Solae LLC provided the soy protein used in the animal diets.