Tea drinkers have stronger bones
As you age, drinking tea helps protect your bones against osteoporosis. Evidence comes from an Australian epidemiological study of a thousand women aged between 70 and 85.
Tea & bones
The researchers did a survey of the factors that protect the skeleton of elderly women for the Australian government. They had already published articles on the positive effect of a diet containing sufficient protein on the skeleton [Am J Clin Nutr. 2005 Jun; 81(6): 1423-8.], an active lifestyle [J Bone Miner Res. 2004 Oct; 19(10): 1634-9.], and a low salt intake [Am J Clin Nutr. 1995 Oct; 62(4): 740-5.].

Other researchers had also discovered that consumption of green and black tea is a factor that affects bone health. [Arch Intern Med. 2002 May 13; 162(9): 1001-6.] [Am J Clin Nutr. 2007 Oct; 86(4): 1243-7.] [Am J Epidemiol. 2003 Oct 15; 158(8): 772-81.] Ergo, thought the researchers, we should look into this too.
And they turned up trumps. Scans showed that the mineral density in the bones [BMD] of the women who drank tea was 3-5 percent higher than the density in the non-tea drinkers.










When the researchers followed a sub-group of the women for four years, they observed that while tea consumption did not prevent bone mass breakdown, it did slow it down by a factor of 2.
Conclusion
If you want to halt osteoporosis without taking medicine, you'd be forced to conclude that most studies show that this pretty hard. Dietary habits and sports reduce bone mass breakdown, but cannot halt it completely. Perhaps a combined approach of, say, Cissus quadrangularis supplementation, a plant-based diet and strength training can help, but so far no human studies have been done to confirm this.

That's why these researchers are pleased with their results. The effects they observed were "greater than the protein effect on lower limb bone density observed by us in this population recently and similar to the effect size of habitual high physical activity", they write. "Thus, overall, our data support the concept that tea intake has beneficial effects on bone structure by reducing bone loss."
Source:
Am J Clin Nutr. 2007 Oct;86(4):1243-7.