Now it’s a midlife protein crisis

ARE you middle-aged and partial to cheeseburgers? A study suggests people like you are at a much greater risk of dying from cancer than your peers on a low-protein diet. But critics say there is no need to alter your diet on the evidence available. Morgan Levine at the University  of Southern California in Los Angeles and colleagues analysed a dietary survey of more than 6300 people in the US aged over 50. Those aged 50-65 at the time of the survey and on a high-protein diet – one where protein supplied a fifth of calories – were 75 per cent more likely to have died over the following 18 years than their peers whose protein intake accounted for less than 10 per cent of calories. The high-protein eaters also LAURI PATTERSON/GETTY–I can has cheezburgerhad a cancer death rate four times that of their low-protein peers (Cell Metabolism, DOI: 10.1016/j. cmet.2014.02.006). But Tim Key from Cancer Research UK says the study is too small to draw robust conclusions. What’s more,  it was based on one survey of what people ate in the previous 24 hours, says Catherine Collins, chief dietician at St George’s Hospital, London. “It implies people’s diet doesn’t  change over 18 years. They are making massive assumptions,” she says. The authors recommend eating less protein in middle age, but Collins disagrees. “We don’t need to do anything different, nor should we be worried about it [on the strength of this study]”, she says.