First, we learned this week that human DNA was found in commercially sold hot dogs.

Now, the World Health Organization's International Agency for Research on Cancer says that bacon, sausage, hot dogs, cold cuts cause cancer - they put them in the same category as cigarettes for cancer risk to humans, particularly colon and stomach cancer. While in the same category of risk, the chances of getting cancer from smoking are significantly higher than that of eating the stated meats.

The WHO's IARC (full report here) says that beef, pork and lamb probably cause cancer to humans.

AICR recommends avoiding processed meats and eating no more than 18 ounces of cooked red meat weekly to lower colo-rectal cancer risk, as they say regular consumption of even small amounts of hot dogs, bacon and other processed meats increase colorectal cancer risk.