Written by Angeline A. De Leon, Staff Writer. Green tea extract in combination with Tai Chi exercise significantly improved biomarkers of bone formation and resorption as well as muscle strength in the participating postmenopausal women with osteopenia.

tai chiDue to marked reductions in estrogen, postmenopausal women are up to four times more likely than men to develop osteoporosis 1. This age-related decrease in bone mineral density (BMD) leads to frailty and increased risk for fractures, particularly in the hip and spine 2. Data from cross-sectional studies suggest that certain bioactive components in tea may exert osteo-protective effects that can help maintain BMD. Polyphenols in green tea extract (GTP) appear to be the most potent in terms of efficacy, functioning to reduce oxidative stress, increase antioxidant activity, and suppress the expression of proinflammatory mediators 3,4. Animal models suggest that GTP may also improve muscle function in rodents 5. In the context of physical activity, Tai Chi (TC), an ancient Chinese martial art known for its use of weight-bearing and mind-body exercise, has also been popularized for its musculo-skeletal health benefits 6. Longitudinal studies now suggest that TC may help preserve BMD and prevent bone loss 7. Although independent lines of research support the clinical benefits of both GTP and TC, their combined application has not been evaluated in postmenopausal women with low bone mass. Researchers at Texas Tech University, therefore, sought to investigate whether GTP intake and TC exercise together could improve biomarkers of bone turnover, calcium metabolism, and muscle strength in postmenopausal osteopenic women.

A total of 171 postmenopausal women with osteopenia were enrolled in a 6-month, randomized, placebo-controlled trial in which they were randomly allocated to one of four groups: placebo (500 mg starch per day), GTP (500 mg GTP per day), placebo plus TC (placebo plus TC exercise for 60 minutes, three days a week), or GTP plus TC. All participants were also supplemented with 500 mg calcium and 200 IU vitamin D daily. At baseline, Month 1, Month 3 and Month 6, overnight fasting blood and urine samples were collected and analyzed for serum bone formation biomarker (bone-specific alkaline phosphatase, BAP), bone resorption biomarker (tartrate-resistant acid phosphatase, TRAP), and calcium metabolism parameters (serum parathyroid hormone, PTH). At baseline, Month 3, and Month 6, muscle strength was measured, and physical activity level was monitored throughout.

Results of the study indicated that GTP groups (GTP and GTP plus TC) had higher serum levels of BAP at Month 1 (p = 0.03) and that TC groups (Placebo plus TC and GTP plus TC) had higher BAP values at Month 3 (p = 0.03). The percent change in BAP/TRAP ratio was also higher for GTP groups, relative to non-GTP groups (Placebo and Placebo plus TC) at Month 3 (p = 0.011), as well as for TC groups, relative to non-TC groups (Placebo and GTP groups) at Month 6 (p = 0.011). Analyses also showed that TC exercise resulted in significant increase in percent change in serum intact PTH levels, compared to non-TC groups, at Month 1 (p = 0.009) and Month 3 (p = 0.035). A significant improvement in static leg strength/endurance (based on wall-sit time duration) was observed for all three treatment groups (Placebo plus TC: p < 0.001; GTP: p < 0.001; GTP plus TC: p = 0.001).

Collectively, evidence suggests that both GTP supplementation and TC exercise independently improve biomarkers of bone formation and bone turnover rate. In combination, GTP and TC can also effectively improve muscle strength in postmenopausal women with osteopenia. Further research is needed to replicate findings, particularly in the form of long-term studies measuring BMD as a primary variable. 

Source: Shen CL, Chyu MC, Yeh JK, et al. Effect of green tea and tai chi on bone health in postmenopausal osteopenic women: a 6-month randomized placebo-controlled trial. Osteoporos Int. 2012; 23(5): 1541-1552. DOI: 10.1007/s00198-011-1731-x.

© International Osteoporosis Foundation and National Osteoporosis Foundation 2011

Posted on January 24, 2018.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

References:

  1. Looker AC, Melton LJ, Harris TB, Borrud LG, Shepherd JA. Prevalence and trends in low femur bone density among older US adults: NHANES 2005–2006 compared with NHANES III. Journal of Bone and Mineral Research. 2010;25(1):64-71.
  2. NIH Consensus Development Panel on Osteoporosis Prevention D, Therapy. Osteoporosis prevention, diagnosis, and therapy. Jama. 2001;285(6).
  3. Shen C-L, Wang P, Guerrieri J, Yeh J, Wang J-S. Protective effect of green tea polyphenols on bone loss in middle-aged female rats. Osteoporosis International. 2008;19(7):979-990.
  4. Shen C-L, Yeh JK, Cao JJ, Tatum OL, Dagda RY, Wang J-S. Green tea polyphenols mitigate bone loss of female rats in a chronic inflammation-induced bone loss model. The Journal of nutritional biochemistry. 2010;21(10):968-974.
  5. Dorchies OM, Wagner S, Vuadens O, et al. Green tea extract and its major polyphenol (−)-epigallocatechin gallate improve muscle function in a mouse model for Duchenne muscular dystrophy. American Journal of Physiology-Cell Physiology. 2006;290(2):C616-C625.
  6. Shen C-L, Williams JS, Chyu M-C, et al. Comparison of the effects of Tai Chi and resistance training on bone metabolism in the elderly: a feasibility study. The American journal of Chinese medicine. 2007;35(03):369-381.
  7. Wolfson L, Whipple R, Derby C, et al. Balance and strength training in older adults: intervention gains and Tai Chi maintenance. Journal of the American Geriatrics Society. 1996;44(5):498-506.
×