After years of research and hundreds of studies finding links between eating certain meats and cancers, health experts have finally broken out the branding irons.

Today, in a sizzling announcement, the International Agency for Research on Cancer (IARC) officially marked processed meat, such as bacon, hot dogs, and sausages, as “carcinogenic to humans,” a “group 1” designation. The agency, an arm of the World Health Organization, also classified red meat, such as beef, pork, and lamb, as “probably carcinogenic to humans,” a “group 2A” grade.

(The group designations refer to the confidence health experts have in the link between the meats and cancer; it does not refer to the potency of the meats’ cancer-causing abilities.)

The conclusion comes from an analysis of more than 800 epidemiological studies reviewed by a panel of 22 experts, who published their results in the Lancet Oncology. The analysis included data that spanned countries, ethnicities, and diets, “which make chance, bias, and confounding unlikely as explanations,” the authors wrote.

The group concluded that there was sufficient evidence that processed meats are carcinogenic to humans, hence the group 1 designation (the strongest confidence classification). The clearest link was between consumption and colorectal cancer. But processed meats have also been linked to stomach cancer.

Among supporting evidence, the panel cited a 2011 meta-analysis, which concluded that every additional 50 grams of processed meat eaten daily raises a person’s relative risk of colorectal cancer by 18 percent.

That study also found that every additional 100g of red meat eaten daily increased the relative risks of colorectal cancer by 17 percent.

Due to limited evidence, the panel was slightly less confident about the link between red meat and cancer, only calling it probably a carcinogen. Though, in addition to colorectal cancer, the panel also found links to pancreatic and prostate cancer.

There’s strong mechanistic data to support an association between meats and cancer. Meat processing methods, such as curing and smoking, form carcinogenic chemicals, including N-nitroso-compounds and polycyclic aromatic hydrocarbons. Cooking red meat with high heat, as is done in grilling, searing, and frying, forms known or suspected carcinogens, including heterocyclic aromatic amines.

Lancet Oncology, 2015. DOI: 10.1016/S1470-2045(15)00444-1 (About DOIs)