A 2007 study by Columbia University suggests a link between eating cured meats, such as bacon, and chronic obstructive pulmonary disease. Nitrites were posited as a possible cause.
Many foods, especially cured meats such as bacon and hot dogs, use nitrates to preserve color and maintain microbial safety. Nitrate is harmless, but it can convert to nitrite (when cooked), which can form nitrosamines, a powerful cancer-causing chemical, in your body. Whenever possible, look for nitrate-free preserved meats. When you do eat foods containing nitrates, have a glass of orange juice at the same time (for instance, orange juice with your morning bacon). Vitamin C is known to inhibit the conversion to nitrosamines in your stomach.
People who eat cured meats are more likely to develop certain diseases such as lung cancer.
One serving a week, max. Bacon is too unhealthy to be consumed on a regular basis (numerous times in a short amount of time).