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 Dietary Prevention of Obesity-related Disease Research: Grand Forks, ND
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ARS Home Plains Area Grand Forks, North Dakota Grand Forks Human Nutrition Research Center Dietary Prevention of Obesity-related Disease Research Research Publications at this Location





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Title:   Author  item
                                            GAFFNEY-STOMBERG, ERIN - Us Army Research Institute Of Environmental Medicineitem
                                            Cao, Jayitem
                                            LIN, GREGORY - Us Army Research Institute Of Environmental Medicineitem
                                            WULFF, CHARLES - Us Army Medical Research Instituteitem
                                            MURPHY, NANCY - Us Army Medical Research Instituteitem
                                            YOUNG, ANDREW - Us Army Medical Research Instituteitem
                                            MCCLUNG, JAMES - Us Army Medical Research Instituteitem
                                            PASIAKOS, STEFAN - Us Army Medical Research Institute
  Submitted to: Journal of Nutrition
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 3/11/2014
                                    Publication  Date: 6/1/2014
                                    Publication URL: http://handle.nal.usda.gov/10113/59614Citation: Gaffney-Stomberg, E., Cao, J.J., Lin, G.G., Wulff, C.R., Murphy, N.E., Young, A.J., Mcclung, J.P., Pasiakos, S.M. 2014. Dietary protein level and source differentially affect bone metabolism, strength, and intestinal calcium transporter expression during ad libitum and food-restricted conditions in male rats. Journal of Nutrition. 144(6):821-829.Interpretive Summary: High protein diets may attenuate bone loss induced by energy restriction (ER).  We investigated whether high protein diets suppress bone turnover and improve bone quality during ER and whether dietary protein source affects this relationship in a rat model.  Eighty 12-week old male Sprague Dawley rats were randomly assigned to eight treatment groups: 10% milk protein, 32% milk protein, 10% soy protein, or 32% soy protein under energy adequate (EA) or ER conditions (40% restriction).  After 16 weeks, markers of bone turnover, bone mineral density (BMD) and structure, and expression of Ca channels in the duodenum were assessed. ER increased bone turnover and resulted in lower femoral trabecular bone volume and higher cortical bone surface compared to EA. High protein intake lowered bone turnover and tended to suppress PTH and increased trabecular BMD. Compared to milk protein, soy protein suppressed PTH, and increased cortical BMD and Ca content of the femur.  During EA conditions, transient receptor potential cation channel, subfamily V, member 6 expression was higher for soy protein than milk protein and high protein compared to normal protein.  These data demonstrate that both high protein and soy protein diets suppress PTH and high protein attenuates bone turnover and increases BMD regardless of energy status, likely due to enhanced intestinal Ca transporter expression.
                                Technical Abstract: High protein diets may attenuate bone loss during energy restriction (ER).  The objective of the current study was to determine whether high protein diets suppress bone turnover and improve bone quality in rats during ER and whether dietary protein source affects this relationship.  Eighty 12-week old male Sprague Dawley rats were randomized to receive one of 4 study diets: 10% milk protein (CP-MP), 32% milk protein (HP-MP), 10% soy protein (CP-SP), or 32% soy protein (HP-SP) under energy adequate (EA) or ER conditions (40% restriction).  After 16 weeks, markers of bone turnover, bone mineral density (BMD) and structure, and expression of Ca channels in the duodenum were assessed.  ER increased bone turnover and resulted in lower femoral trabecular bone volume (P < 0.05) and higher cortical bone surface (P < 0.001) compared to EA.  High protein intake lowered bone turnover and tended to suppress PTH (P = 0.06) and increased trabecular BMD (P < 0.05) compared to CP.   Compared to MP, SP suppressed PTH (P < 0.05), and increased cortical BMD (P < 0.05) and Ca content of the femur (P < 0.01).  During EA conditions, transient receptor potential cation channel, subfamily V, member 6 expression was higher for SP than MP (P < 0.05) and HP compared to CP (P < 0.05).  These data demonstrate that both HP and SP diets suppress PTH and HP attenuates bone turnover and increases BMD regardless of energy status.  These findings may be due in part to enhanced intestinal Ca transporter expression.


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