The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) evaluated more than 800 studies to understand the link between processed meats and cancer. The studies excluded other cancer-causing factors such as obesity, so the effect of processed meats could be isolated.
The IARC working group was chaired by UNSW Medicine & Health Professor Bernard Stewart, who is an internationally recognized expert on environmental carcinogenesis (cancer causation).
Ultimately, the IARC classified processed meat as carcinogenic, meaning it found enough evidence that eating processed meat causes colorectal cancer. This is due to nitrites found in processed meat products.
The evidence that processed meats cause cancer is as definitive as the evidence that tobacco smoke and asbestos cause lung cancer. Different carcinogens have different levels of impact on cancer risk. For tobacco smoke, the impact is high: the lifetime risk of lung cancer in a non-smoker is 1% and in a heavy smoker it is 25%. However, for someone who consumes processed meat frequently rather than in moderation, their lifetime risk of colorectal cancer increases to 5% to 6%.
This means that while there is strong evidence that eating processed meats causes colorectal cancer, the actual impact on cancer risk is relatively small. Although eating salami may not be as dangerous as smoking cigarettes or breathing in asbestos particles, it does contribute to cancer. But there may be ways to counteract the effects of processed meats on your gut, at least partially. This includes eating foods like fruits, vegetables, and whole grains. Whole grains may have an indirect effect by fighting obesity, but they also directly prevent cancer activity within the intestine. Importantly, whole grain dietary patterns could mean disease prevention, saving millions in healthcare costs.
Source: Provided by the University of New South Wales.