Eating too much bacon or other cured meats increases the chance of developing chronic lung diseases, a US study quoted by the BBC shows.
Researchers from the Columbia University found that eating cured meats at least 14 times a month increased one's chance to develop a chronic obstructive pulmonary disease (COPD), a category that includes chronic bronchitis and emphysema.
The high level of nitrites, used to preserve the meat and kill bacteria, may be the main reason, according to the study.
The study looked at 7,352 Americans who participated in a survey between 1988 and 1994.
Although many of them had an unbalanced diet, that factor held little influence over the development of lung diseases.
Smoking is the biggest single cause of COPD in the world.