Processed meat is made available to eaters for a long time after its manufacture by treating it for preserving with salting, smoking, fermenting and curing. Such processed meat, including hams, sausages, bacon, deli meat is known to be a potential cause of cancer and classified a carcinogen by the International Agency for Research on Cancer (IARC) of World Health Organization (WHO). Red meat, comprising of pork, beef, goat, and lamb is stratified as a probable cause of cancer by IARC.
Further research studies have generated inconsistent results associating processed and red meat consumption with breast cancer risk. All the published studies related to this topic have been examined in an analysis by the International Journal of Cancer. 15 studies were included in the analysis and it was revealed via comparison of highest to the lowest category that consumption of processed meat was linked to 9% higher breast cancer risk. However, red (unprocessed) meat intake show 5% increase in breast cancer which is not quite significant. The relationship between red meat and breast cancer depends on the genotypes of patients regarding N-acetyltransferase 2 acetylator that has been evaluated in detail in 2 studies. The cancer-causing effect of meat is modified due to the activity of this enzyme. No link was established by researchers among patients with either slow or fast N-acetyltransferase 2 acetylators.
Previously, some other cancers were related with increased processed and red meat consumption, like colon, prostate and pancreatic cancers. Recent studies and meta-analysis relate increased breast cancer risk to red and processed meat intake. Dr. Maryam Farvid from Harvard T.H. Chan School of Public Health stated that in order to prevent breast cancer, one must cut down processed meats from the diet.