|Lykken, Glenn - UNIV. OF NORTH DAKOTA|
Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 2000
Publication Date: March 7, 2001
Citation: Roughead, Z.K., Lykken, G.I., Hunt, J.R. 2001. Controlled high meat diets do not affect calcium retention or indices of bone status in healthy postmenopausal women. The Federation of American Societies for Experimental Biology Journal. 15:A727. Technical Abstract: It is well established that an increased intake of purified proteins leads to an increased urinary calcium loss, however, the effects of common sources of dietary protein on calcium economy have not been tested with a calcium radiotracer, under controlled diet conditions. Calcium retention from a high meat (HM) and a low meat (LM) diet was determined in a controlled feeding study of healthy postmenopausal women. The subjects consumed the LM or HM diets (12 vs. 20% of energy as protein, 1.5 oz vs. 10 oz of meat, respectively, with 700 mg calcium/2200 kcal), for 8 wk each, in a randomized crossover design. After 4 wk of equilibration, the entire 2-d cycle menu was labeled with Ca-47 radiotracer (as CaCl2) and its retention was monitored for 4 wk by whole body scintillation counting. The calcium retention data, expressed as a percentage of the initial dose (mean +/- SD), were modeled by a two-component exponential equation (individual R**2 ranged from 0.98 to 0.99). The biological half-life of the isotope was longer (p<0.04) on the HM diet (56 +/- 6 d) than the LM diet (40 +/- 4 d), however, the final retention of the isotope, 28 days after its administration, was similar between the diets (15.8% +/- 4.0 and 17.2% +/- 4.2 for LM and HM, respectively, p = 0.09). Biomarkers of bone formation or bone resorption, and urinary calcium excretion measured at the end of each dietary period (wk 8) were not different between the two dietary treatments. In conclusion, consuming a high meat diet for 8 weeks did not increase calcium requirements or adversely affect indicators of bone status in healthy postmenopausal women. Partially funded by the North Dakota Beef Commission.