A round-up of the week's other medical news in brief ...
Scientists astounded by blindsight
A man left totally blind by brain damage has astounded scientists by flawlessly navigating an obstacle course without the help of a cane.
Experts believe it was the most dramatic demonstration yet of "blindsight" - the strange ability some blind people have to detect things they cannot see.
The man, known as TN, suffered damage to both sides of his brain from consecutive strokes and is completely blind. Scientists investigating TN's blindsight ability constructed an obstacle course consisting of randomly arranged boxes and chairs. TN was then asked to cross it without help.
Astonishingly, he managed to get through the course without once bumping into an obstruction. The study was led by Prof Beatrice de Gelder, from the University of Tilburg in the Netherlands.
Ball games good for teen bones
Playing ball games as a teenager can help keep bones healthy for more than 40 years, researchers said today.
Weight-bearing exercises such as handball, softball, volleyball, tennis and basketball keep bones strong into older age. The same can be said for high-impact sprinting, the study on sport played between the ages of 12 and 18 found.
The research was led by Dr Takeru Kato, from the Suzuka University of Medical Science in Japan.
Any extra weight poses heart risks
Even a little bit of extra weight can raise the risk of heart failure, according to a US study published yesterday that calculated the heart hazards of being pudgy but not obese.
But researchers who tracked the health of 21,094 US male doctors for two decades found that even those who were only modestly overweight had a higher risk and it grew along with the amount of extra weight.
The risk of heart failure rose on average by 11 per cent over the next 20 years, the researchers wrote in the journal Circulation.