In a blink of an eye, five years have passed and the Scientific Report of the 2020 US Dietary Guidelines has been published. The health consequences of eating processed meats like hot dogs, bacon, and deli meat were evident when the 2015 guidelines were set, and the research to eat them sparingly has continued to accumulate. (1)
Processed meat and cancer
Processed red meat differs from fresh red meat in that it’s been cured, salted, smoked, canned, or treated with preservatives. Processed red meat includes foods like bacon, sausage, hot dogs, bologna, corned beef, salami, ham, and beef jerky. Fresh beef or steak or lamb without preservatives is not considered processed.
In 2015, following the review of over 800 epidemiological studies by 22 experts from 10 countries, the WHO’s International Agency for Research on Cancer identified consumption of processed meat as “carcinogenic to humans on the basis of sufficient evidence for colorectal cancer”. A meta-analysis found that each 50-gram portion of processed meat consumed daily raises the risk of colon cancer by 18%. This is the equivalent of just one hot dog a day!
In addition, the risk for breast, prostate, pancreatic, and overall cancer mortality increases with the daily consumption of 50 grams of processed meat. Experts suspect that pro-oxidative compounds, heme iron, and nitrosamines in processed meats have carcinogenic effects. (2, 3)
Processed meat, red meat, and heart disease
Research shows that processed meat also raises the risk of death from cardiovascular disease. A 2017 systematic review of studies on food groups and risk for coronary heart disease, stroke, and heart failure found positive links between processed and red meat consumption and the risks of coronary heart disease, stroke, and heart failure. Eating up to 150 grams of red or processed meat per week is associated with a 10-20% increased risk in dose-response analyses. Red meat intake also raised the risk of stroke and heart failure by 15 to 25% with an intake of up to 70 grams daily. (4)
Red meat (both processed and unprocessed) may raise the risk of CHD, particularly in men. A 2020 prospective cohort study in over 43,000 subjects, found 4456 CHD events, 1860 that were fatal. After adjusting for various factors, total, processed, and unprocessed red meat intake were all linked with a modestly higher risk of CHD with a hazard ratio for one serving per day: 1.12 for total red meat, 1.15 for processed red meat, and 1.21 for unprocessed red meat. (5)
Red meat and diabetes
The link between red meat intake and diabetes is also evident. The 2017 Singapore Chinese Health Study evaluated the consumption of red meat, poultry, fish, heme iron, and risk for type 2 diabetes. Intake of heme iron from red meat increased the risk for diabetes. A stronger correlation was seen in women than men, which the authors believe may be due to increased iron absorption in the gut. The researchers found that replacing 1 daily serving of red meat with fish or shellfish was significantly associated with a 26% lower risk. (6)
Environmental concerns of red meat
In addition to being hard on us physically, red meat intake is also hard on the environment. Global warming, increased methane gas emissions, and increased use of natural resources are just a few issues. According to the EPA, 500 million tons of manure are produced by factory-farmed animals. Runoff from these farms contributes to bacterial contamination and pollution in lakes and rivers. Meat production uses lots of water. It takes 150 gallons of water to produce a quarter-pound of beef. 6 Unfortunately, changing behaviors can be challenging. (7)
A recent systematic review of 34 studies on consumer attitudes towards environmental concerns and meat intake showed that while most are aware of the impact of meat on the environment, have changed, or are willing to change habits are in the minority. In the US and UK, vegetarians account for only 5% of the population. Those that were more likely to change habits due to the environment were more likely young, female, ecology-oriented, and live outside of the US. (8)
While giving up red meat completely may prove difficult, there are plenty of plant-based proteins for consumers to choose from.
- Tofu, tempeh, and other soy-based products are complete proteins that can be used in traditional meat dishes such as stir-fries, grain bowls, or salads.
- Low-fat and fat-free dairy products also offer high-quality protein. Greek yogurt, skim and 1% milk, and light and non-fat cheese are good options.
- Dried beans, lentils, and legumes are also versatile sources of protein. Pair them with a whole grain such as quinoa, farro, brown rice, bulgur, or barley.
- Nuts, seeds, and nut butter also provide dietary protein. The new US Dietary Guidelines advise us to include these more frequently in our diets.
If you can’t go completely without red meat, that’s OK. Replacing ground beef with lean ground turkey or having fish more frequently in your diet is a good place to start. Using a small amount of lean red muscle meat or ground beef is always better than processed meats, too. And beans make a great meal a few times a week! It is always great to try new thing!
Lisa Andrews, MEd, RD, LD
- Mozaffarian, D. 2016. Dietary and policy priorities for cardiovascular disease, diabetes, and obesity: A comprehensive review. Circulation 133:187–225
- Angela Bechthold, Heiner Boeing, Carolina Schwedhelm, Georg Hoffmann, Sven Knüppel, Khalid Iqbal, Stefaan De Henauw, Nathalie Michels, Brecht Devleesschauwer, Sabrina Schlesinger & Lukas Schwingshackl (2019) Food groups and risk of coronary heart disease, stroke, and heart failure: A systematic review and dose-response meta-analysis of prospective studies, Critical Reviews in Food Science and Nutrition, 59:7, 1071-1090, DOI: 10.1080/10408398.2017.1392288
- Al-Shaar L, Satija A, Wang DD, Rimm EB, Smith-Warner SA, Stampfer MJ, Hu FB, Willett WC. Red meat intake and risk of coronary heart disease among US men: prospective cohort study. BMJ. 2020 Dec 2;371:m4141
- Mohammad Talaei, Ye-Li Wang, Jian-Min Yuan, An Pan, Woon-Puay Koh, Meat, Dietary Heme Iron, and Risk of Type 2 Diabetes Mellitus: The Singapore Chinese Health Study, American Journal of Epidemiology, Volume 186, Issue 7, 1 October 2017, Pages 824–833
- Sanchez-Sabate, R.; Sabaté, J. Consumer Attitudes Towards Environmental Concerns of Meat Consumption: A Systematic Review. Int. J. Environ. Res. Public Health 2019, 16, 1220.
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