Nitrates and nitrites prevent spoiling and give taste and color to cured meats like hot dogs, bacon, sausage, ham, and lunch meat. They can also convert to a substance known to cause cancer in animals.
Studies show that eating a lot of processed meats for 10 years doubles your risk of colorectal cancer.
What's a lot of cured meat? For women, it's two slices of bacon or half a hot dog two to three times a week. For men, it's that amount five to six times a week, says a 2005 JAMA study. Even eating smaller amounts over time increases colorectal cancer risk.