One drink of beer a day can prevent cataracts. Scientists in Canada carried out tests on rat lenses and found that antioxidants, like those in beers, protected cells in the eye which, if damaged, lead to an increase in cataracts. They say that high glucose levels damage key elements of cells called the mitochondria. These are mini-organs that are responsible for converting glucose into the energy needed by cells to function properly. When the mitochondria found in the cells of the outer lens of eye are damaged in this way it can lead to the development of cataracts. John Trevithick, who presented the research at the International Chemical Conference in Honolulu on December 17, said that the finding could help diabetics ( BBC online , December 18).