We hear a lot about consuming fewer processed foods as a key strategy to improve health. The 2020-2025 Dietary Guidelines for Americans encourages choosing unprocessed meats instead of processed meats.
But just what are processed meats and why should we avoid them?
What are Processed Meats?
According to the Meat Institute, meat processing started centuries ago. Salting and smoking preserved meats and kept them safe to eat for longer periods of time in the days before people had refrigerators or freezers. While those practices made it possible to preserve meat for later use, today processed meats aren’t a necessity. Yet they are often part of our daily or weekly food choices.
The American Institute for Cancer Research/World Cancer Research Fund expert report defines processed meat as meat preserved by smoking, curing, or salting, or by using chemical preservatives. Some processed meats are ready-to-cook such as breakfast sausages, kielbasa, hot dogs, or a marinated turkey breast or salmon filet. Other processed meats are ready-to-eat without cooking, such as bologna, salami, summer sausage, and other types of lunchmeat.
Why are Processed Meats Unhealthy?
A number of studies found links between processed meat and various forms of cancer, heart disease, and diabetes.
In 2015, the International Agency for Research on Cancer (IARC) classified processed meats as a Group 1 carcinogen for human colorectal cancer which means that there is sufficient scientific evidence that processed meats cause cancer. Nitrates and nitrites added during processing are believed to damage the cells that line the colon and rectum, which can lead to cancer. Heterocyclic amines and polycyclic amines produced when meat is cooked at high temperatures during processing can also cause damage to these cells that in turn leads to cancer.
According to The Academy of Nutrition and Dietetics, nitrate is chemically reduced to nitrite in the curing process. Nitrite is then converted to nitric oxide when it reacts with the pigment in meat. This reaction stabilizes the color we associate with processed meat products like hot dogs, bacon, and ham. Nitrate also protects against the deadly bacteria Clostridium botulinium which causes botulism. Consuming nitrates and nitrites have been shown to damage DNA, which makes them carcinogenic.
What About Nitrate-Free Meats?
In response to consumer demand to remove dangerous nitrates from processed meats, some food processors started using celery powder instead of chemicals. These companies then labeled their meat products as "uncured" or "no nitrate or nitrite added." However, the Center for Science in the Public Interest (CSPI) petitioned the U.S. Department of Agriculture (USDA) to revise its regulations because these labels are misleading. Tests of these foods show that nitrates and nitrites are found at similar levels as foods prepared with synthetic curing agents and therefore are not a healthy option.
By Lynn Grieger, RDN, CDCES, CHWC, CPT
For more about processed meats, don't miss the post Alternatives to Processed Meats.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. Available at DietaryGuidelines.gov
- American Institute for Cancer Research. What is Processed Meat Anyway? https://www.aicr.org/resources/blog/what-is-processed-meat-anyway/ published 2-23-12; accessed 3-28-21
- American Meat Institute. Processed Meats: Convenience, Nutrition, Taste. https://www.meatinstitute.org/index.php?ht=a/GetDocumentAction/i/94559%2520date accessed 3-28-21
- Harvard T.H. Chan School of Public Health. Are All Processed Meats Equally Bad for Health? https://www.hsph.harvard.edu/news/hsph-in-the-news/are-all-processed-meats-equally-bad-for-health/ accessed 3-28-21
- Bouvard V, Loomis D, Guyton KZ, et al.; International Agency for Research on Cancer Monograph Working Group. Carcinogenicity of consumption of red and processed meat. Lancet Oncol 2015;16:1599–1600
- Cunningham E. Dietary nitrates and nitrites-harmful? Helpful? Or paradox? J Acad Nutr Diet. 2013 Sep;113(9):1268. doi: 10.1016/j.jand.2013.07.014. PMID: 23972273.
- The University of Texas MD Anderson Cancer Center. Processed Meat and Cancer: What You Need to Know. Danielle Underferth. https://www.mdanderson.org/publications/focused-on-health/eat-less-processed-meat.h11-1590624.html published February 2016; accessed 3-29-21
- Center for Science in the Public Interest. USDA to Improve Misleading Processed Meat Labels. https://www.cspinet.org/news/usda-improve-misleading-processed-meat-labels-20201211 published 12-11-20; accessed 3-30-21
Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.