there *may* be something in this, although I can't get past the abstract and see the full study of the bone thickness study.
http://www.ncbi.nlm.nih.gov/pubmed/20306019

As usual though the journalist misses out some key points such as the research was done on RATS and has not been repeated on humans. Nor can I find a study that repeats the findings of this study.
It's a far cry from "scientists say green tea is good for you"

Blame poor journalism, not science.