The Effects of Protein Supplementation on Bone Mass in Chinese Postmenopausal Women
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Background: Sufficient calcium intake is essential for the maintenance of bone health in older people. However, the effect of dietary protein on bone mass of older women has been controversial. To the best of our knowledge, there has been no clinical trial evaluating the effect of protein supplementation on bone mass in older Chinese women.
Objective: To evaluate the effect of 1-year protein and calcium supplementation on bone mass in older Chinese women compared to calcium supplementation alone.
Design: A 1-year randomized controlled trial was conducted in 283 Chinese postmenopausal women aged 68.1 ± 0.5 years (range 60–86 years). Study participants were randomized to receive either protein powder containing 30 g soybean protein and 1,000 mg calcium as calcium carbonate (Pro + Ca group, n = 142) or only 1,000 mg calcium per day (Ca group, n = 141). Measurements performed include dietary intakes by 1-year food-frequency questionnaire, physical activity by International Physical Activity Questionnaire (IPAQ)-Short Form, and areal bone mineral density (aBMD) at hip, lumbar spine (L2–L4), and total body by DXA at baseline and 1 year later.
Results: There were no significant differences between the two groups in baseline characteristics. With supplementation, both groups had significantly higher calcium intake compared to the baseline (1,647 ± 53 mg/day vs. 879 ± 30 mg/day, P = 0.01), and the average dietary protein intake was significantly higher in the Pro + Ca group compared to the Ca group (107.8 ± 4.6 g/day vs. 75.7 ± 3.1 g/day, P < 0.001).
After 1-year supplementation, there was a slight but significant increase in aBMD at total body, femoral neck, trochanter, and total hip in both groups after adjusting for baseline age, BMI, calcium intake, physical activity level, and serum 25(OH)D level (time effect, all P < 0.05). There were no significant time effects on lumbar spine aBMD in either group.
The Pro + Ca group had significantly greater increase in total-body aBMD (9.5 mg/cm2) compared to the Ca group (0.4 mg/cm2) after 1 year of supplementation before adjustment for covariates (time × group interaction, P < 0.05). There were no significant effects of protein supplementation on aBMD of other sites.
Conclusion: Higher intake of dietary protein might have a positive effect on total-body bone mass in Chinese postmenopausal women when calcium intake is sufficient.
KeywordsProtein Bone mineral density Calcium Postmenopausal women
- 1.Zhao D, Wu H, Liu Z. The epidemiology of osteoporosis in China. Chin J Osteoporos. 2004;10:614–8.Google Scholar
- 8.Wang DL. Report of China National Nutrition and Health Survey in 2002 I: total report. Beijing: Public Health; 2005.Google Scholar
- 9.Yang Y, Wang G, Pan X. China food composition 2002. Beijing: Peking University Medical Press; 2002.Google Scholar
- 10.Yang Y. China food composition 2004-book 2. Beijing: Peking University Medical Press; 2004.Google Scholar
- 11.Chinese Nutrition Society. Chinese DRIs. Beijing: Chinese Light Industry Press; 2000.Google Scholar
- 13.National Health and Medical Research Council. Dietary guidelines for protein intake affects bone mass 1427. Canberra: Australian Government Publishing Service; 1991.Google Scholar