What is processed meat?

The World Health Organization just released recommendations based on hundreds of studies finding that processed meat causes cancer, and red meat probably does.

So what exactly is processed meat?

The WHO report defines it as "meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavor or improve preservation."

Red meat is defined as unprocessed mammalian muscle meat such as beef, veal, pork, lamb, mutton, horse, or goat meat, including minced or frozen meat.

Most processed meat contains pork or beef, but also can include other red meats, poultry, as well as organs or blood.

These are some of the most common processed meats:

• bacon
• ham
• hotdogs/sausages
• salami
• corned beef
• beef jerky
• canned meat
• meat-based sauces

The WHO report looked at more than 800 studies on cancer and consumption of red meat or processed meat across many different countries, ethnicities, and diets.

The authors found considerable evidence that processed meat is linked to colorectal cancer, and to some extent, stomach cancer. There was not enough evidence to suggest that red meat causes cancer, but the report found a probable link.

And the risk of cancer is related to the amount of meat consumed.

According to studies cited in the WHO report, for every 50 grams of processed meat you eat per day (just over one beef hot dog), your risk of colorectal cancer goes up by 18%. And for every 100 grams of red meat you eat per day (slightly less than a quarter-pounder), your colorectal cancer risk could go up by 17%. But once you go above 140 grams of meat per day, the cancer risk plateaus, meaning it doesn't get higher or lower once you eat that amount or more.

Processed meat joins a host of other substances that have been found to cause cancer, including cigarette smoke, asbestos and arsenic, though the WHO report didn't compare these risks directly.