Osteoporosis is the most common type of bone disease, but many people who develop it do not know they have it until the disease is in an advanced stage and they suffer from a fracture or bone break. It is more common in women – researcher estimate that 1 out of 5 American women over the age of 50 have it – but it can also affect men as they age.
This degenerative disease occurs when the body does not form enough new bone, when too much old bone is reabsorbed by the body, or both. It is primarily caused by a loss of estrogen in women at menopause and a loss of testosterone in men.
Osteoporosis is not curable, but treatment can help strengthen bones, slow down or stop bone loss, control pain, and decrease the risk of falls and fractures. Strength-building exercise and calcium and vitamin D3 supplementation are some of the most common treatment recommendations.
A recent study in Osteoporosis International looked at the effect of green tea and tai chi on bone health in postmenopausal osteopenic women. Osteopenia is a pre-cursor to osteoporosis in which a person’s bone mineral density (BMD) is lower than normal but not low enough to classify as osteoporosis.
For the six-month study, 171 osteopenic women who were at least two years past menopause were randomly assigned to four groups. Group 1 was given a placebo of 500 milligrams (mg) of starch per day. Group 2 was given 500 mg of supplemental green tea polyphenols (GTP) a day. Group 3 was given the placebo and participated in 60 minutes of tai chi three times a week. And group 4 took the GTP supplement and also participated in the tai chi training. In addition, all participants were given 500 mg of calcium and 200 IU of vitamin D (cholecalciferol) daily.
Bone turnover biomarkers, calcium metabolism and muscle strength were measured at baseline and then one, three and six months into the study. Muscle strength was evaluated at baseline, and at three and six months. One hundred and fifty subjects completed the study.
The authors cited past research that has shown that tea, specifically green tea, and its bioactive component (i.e., GTP) may benefit bone health by maintaining bone mineral density (BMD) and reducing risk of fracture. And tai chi, a traditional Chinese form of martial arts that involves a series of slow, controlled movements repeated in patterns, has shown the potential to benefit musculoskeletal health in terms of decelerating bone loss, preserving BMD or improving neuromuscular function.
So what did they determine in this new study? Here are some of the highlights:
Bone Turnover Biomarkers: Bone-specific alkaline phosphatase (BAP) is an index for the rate of bone formation. GTP intake and tai chi (the supplements alone and the combination of supplements and exercise) affected serum BAP at one month, while tai chi (alone and with GTP) led to higher BAP values at three months. Neither GTP supplementation nor tai chi had any effect on the levels of serum tartrate-resistant acid phosphatase (TRAP) levels, which is a bone resorption biomarker. No changes in serum BAP and TRAP were seen due to tai chi and GTP at six months, which authors hypothesized may be related to the bone adaptation.
Results of the changes in the BAP/TRAP ratio, an indicator of the state of bone turnover, were similar to the findings above, and due to increased bone formation rather than decreased bone resorption, which suggests that GTP intake and tai chi increased bone formation.
Calcium Metabolism: Calcium metabolism is the mechanism by which the body maintains adequate calcium levels. Tai chi (alone and with GTP) induced a significant elevation in the percent change in serum intact parathyroid hormone (PTH) levels at one month and three months compared to those in the non tai chi groups.
Muscle Strength: The loss of estrogen in postmenopausal women and physical inactivity contributes to the loss of muscle mass and strength, and some recent studies have suggested that postmenopausal women with lower lean muscle mass or strength in their legs and trunk are at a higher risk for osteoporosis. Using a wall-sit test to determine muscle strength, the placebo group showed no statistically significant change in muscle strength, while the GTP, tai chi and combination group showed significantly improved participants’ static leg strength and endurance.
A Recipe for Strong Bones
Putting it all together, for both men and women concerned with their bone health and preventing osteoporosis, it seems a regimen of supplementation and strength-building exercises is a good way to go.
In addition to drinking green tea or taking GTP supplements, you should take a calcium and vitamin D supplement. The recommended dietary allowance for calcium is 1,200 mg a day. And for vitamin D, the National Academy of Sciences considers 2,000 IU the safe daily upper limit.
Whether you’re at or nearing an age where osteoporosis is a concern, or simply want to get a head start, these are great steps toward strengthening your bones.
 Shen, CL, et al. Effect of green tea and Tai Chi on bone health in postmenopausal osteopenic women: a 6-month randomized placebo-controlled trial. Osteoporosis International. 2011 July 15.