Women are most at risk of violence - often sexual - from their partners, according to a survey of more than 24,000 women in 10 countries by the World Health Organisation. Apart from Japan, no major developed countries were included. In 13 of 15 places surveyed, more than one in four women said they had been attacked by a partner at some stage - often severely, AFP reports. The safest place surveyed was Yokohama; and the most dangerous Butajira, a rural district in Ethiopia, where more than seven out of 10 women reported having been attacked.

Boning up on fizzy drinks

Women who drink cola every day have significantly weaker bones than those who drink it once a week or not at all, according to analysis of studies of more than 2,500 women published in the American Journal of Clinical Nutrition. The effect was less for decaffeinated cola. Men's bones weren't affected, healthday.com reports. Lower bone density can lead to osteoporosis, which can cause bone fractures, particularly in the hips.

Diet drinks boost booziness

Drinking alcohol with artificially sweetened mixers makes you drunker, according to Australian research, which found that diet mixers pass through the stomach faster, resulting in significantly sharper spikes in blood-alcohol levels. Using a diet mixer could mean the difference between driving legally or not, says team leader Christopher Rayner of Royal Adelaide Hospital. Although the study was done on young men, the researchers say that women's blood alcohol levels are typically higher than men's after drinking the same amount of alcohol, Reuters reports.

Stressed? Have a cuppa

There's nothing like a nice cup of tea, after all, for calming the nerves - and plain black tea works just fine, according to a study of 75 tea-drinking men by researchers from University College London. 'Drinking black tea may speed up our recovery from the daily stresses in life,' says researcher Andrew Steptoe. Tea doesn't reduce the stress experienced, but it seems to help 'in bringing stress hormone levels back to normal' faster, Reuters reports. It's not clear which ingredients are responsible for the stress recovery and relaxation.

No IQ increase from breast milk

Breast-fed children are smarter than those who are bottle-fed - but it's not the milk. It's just that their mothers are smarter, according to an analysis of data from more than 5,000 children and 3,000 mothers in the US. 'When this was taken into account, most of the relationship between breast-feeding and the child's intelligence disappeared,' says study co-author Geoff Der from Britain's Medical Research Council. But the researchers say the benefits of breast-feeding remain significant, including a stronger ability to ward off infection, AP reports.

X marks the spot for selfishness

Swiss scientists say they may have found the area of the brain that controls selfishness, based on studying 52 men offered a series of fair and unfair monetary deals, worth no more than about US$20 each. For the record, it's the right dorsolateral prefrontal cortex (DLPFC). The most selfish players, consistently, were those whose DLPFCs had been given a magnetic shock, WebMD reports. University of Zurich researchers say the findings may shed light on disorders marked by 'excessive selfish tendencies and a failure to obey basic social norms'.

Jason Sankey is a tennis professional