associated with an increased risk of diabetes, cardiovascular disease, cancer (particularly colorectal cancer), and all-cause mortality. These associations are strongest for processed meat, which is meat that has undergone salting, curing, fermentation, smoking, or other processes to enhance flavor or improve preservation, such as bacon, ham, salami, pepperoni, hot dogs, and some sausages. A 2021 umbrella review that sees an increase of 11–51% risk of multiple cancer per 100g/d increment of red meat, and an increase of 8-72% risk of multiple cancer per 50g/d increment of processed meat. A 2022 study challenged the dose-response relationship using a newly developed burden of proof risk function (BPRF). It found weak evidence available regarding whether eating red meat increases the risk of death. The authors conclude that the quality of the available evidence is insufficient to make stronger or more conclusive recommendations regarding the health effects of eating red meat. However the BPRF approach has been criticised for being overly simplistic. Cancer The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) classifies processed meat as carcinogenic to humans (Group 1), based on "sufficient evidence in humans that the consumption of processed meat causes colorectal cancer." Unprocessed red meat is categorised as "probably carcinogenic to humans (Group 2A), based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect." Positive associations have also been observed between red meat consumption and increased risks of pancreatic cancer and prostate cancer but the link is not as clear. The American Institute for Cancer Research, Cancer Research UK and World Cancer Research Fund International have stated there is strong evidence that consumption of processed red meat is a cause of colorectal cancer and there is probable evidence that unprocessed red meat is a cause of cancer. Put in perspective, in the UK, 56 out of 1000 people who eat the lowest amount of processed meat will develop colorectal cancer (5.6%) while 66 out of 1000 high processed meat eaters will develop colorectal cancer (6.6%). Mechanisms Nitrates and nitrites found in processed meat can be converted by the human body into nitrosamines that can be carcinogenic, causing mutation in the colorectal cell line, thereby causing tumorigenesis and eventually leading to cancer. Processed meat is more carcinogenic compared to red meat because of the abundance of potent nitrosyl-heme molecules that form N-nitroso compounds. A