Dr Dominique Michaud of the Harvard School of Public Health in Boston and her colleagues looked at data for 47,422 men and 88,471 women. Over 22 years, 808 developed bladder cancer. Those who ate five or more portions of bacon were a week were 60% more likely to develop bladder cancer.
Nitrosamines, which are known bladder carcinogens, or their precursors are found in certain meat items, and concentrations of these compounds are especially high in bacon. However, the researchers found other factors may have influenced the result, such as the fact that people who eat lots of bacon are more likely to smoke and eat too much fat, and are less likely to exercise.
A spokesperson for BPEX said: "They're looking at consumption far in excess of what's eaten in this country. If you eat vast amounts of anything it is potentially dangerous."