The key ingredient is thought to be lycopene, the antioxidant already credited with cutting the risk of prostate cancer in men and protecting against heart disease.
Researchers at the University of Toronto in Canada asked 60 post-menopausal women, aged 50 to 60, to cut out all tomato products from their diet for a month.
This led to a significant increase in blood levels of N-telopeptide, a chemical released into the bloodstream when bone is being broken down.
Then, for four months, the women were given a daily dose of standard tomato juice containing 15mg of lycopene, an enriched version with 35mg of lycopene, lycopene capsules or dummy capsules.
This led to a significant drop in levels of N-telopeptide in women drinking either type of juice or taking the capsules. But there was no benefit in women taking the dummy capsules.
Standard supermarket juice was just as good as the lycopene-enriched one, said researchers.
Two glasses a day of tomato juice containing 15mg of lycopene could be enough to strengthen brittle bones, the journal Osteoporosis International reported.
Microsoft is now valued by investors at $219bn.
The worth, known as market capitalisation, is calculated by multiplying the number of shares in a company by the current share price.
Although Apple shares closed down 0.4%, Microsoft fell by 4%.
Apple, which makes computers, iPods, iPhones and now iPads, almost went out of business in the 1990s.
Its growth is partly owing to the launch of the stylish iPod in 2001.
Its compatability with existing - but not mass-selling - Apple computers lead customers to engage with them, just as Microsoft's products looked set for long-term dominance. Hey-day
Apple has to look back to late 1989 to see the last time it was ahead of Microsoft.
Microsoft, whose operating system runs on more than 90% of the world's personal computers, has not been able to match growth rates from its hey-day of the 1990s, although its last sales figures were still higher than Apple's.
This week sees the launch in Britain and eight other countries of Apple's iPad tablet computer.
Next month will see the unveiling of the next generation of the iPhone, something that has brought internet access on the move to the mass market, and led to an explosion in downloadable mobile "apps" - applications that enable a huge range of activities, from map reading to booking restaurants.
About Me
