Eating too much protein could be as dangerous as smoking for middle-aged people, a scientific study has found.
Research which tracked thousands of adults for nearly 20 years found that people who eat a diet rich in animal protein are four times more likely to die of cancer than someone with a low protein diet.
The risk is nearly as high as the danger of developing cancer by smoking 20 cigarettes each day.
Previous studies have shown a link between cancer and red meat, but it is the first time research has measured the risk of death caused by regularly eating too much protein.
Nutritional advice has traditionally focused on cutting down on fat, sugar and salt. The World Health Organisation will announce a consultation today suggesting that guidelines on sugar consumption should be lowered, but there have few warnings about excess protein.
The US study found that people with a high protein diet were 74 per cent more likely to die of any cause within the study period than their low-protein counterparts. They were also several times more likely to die of diabetes. But this trend appeared to reverse for those aged over 65, researchers found. . .