Which food processing method has been linked to cancer in laboratory animals?

Smoke curing has been linked to cancer in laboratory animals primarily due to the formation of polycyclic aromatic hydrocarbons (PAHs) and nitrosamines during the smoking process. These compounds are known carcinogens and can form when organic materials are burned or charred. The smoke produced during curing can deposit these harmful substances onto the food, leading to potential health risks when consumed over time.

In contrast, pickling, freeze-drying, and irradiation do not produce the same carcinogenic compounds associated with smoke curing. Pickling typically involves acids that can inhibit bacterial growth without introducing harmful carcinogens. Freeze-drying is a preservation method that removes moisture while retaining nutrients, and it doesn’t entail exposure to high temperatures or smoke that could generate carcinogens. Irradiation is a technique used to kill bacteria and parasites as well as extend shelf life, and extensive studies have not shown a direct link to cancerous effects in the same way as smoke curing. Therefore, smoke curing stands out as the method with clear associations with carcinogenic risk in laboratory studies.