As colon cancer becomes increasingly common around the world, scientists are racing to understand what causes—and prevents—the disease. It’s well-known that many factors, including family history, underlying health problems, and lifestyle, play a role in the development of colon cancer. One of the biggest concerns to oncologists? Diet.

Recent evidence suggests that eating a lot of sugar, red meats, and processed meats, like bacon, deli meats, and hot dogs, is linked to a greater chance of developing colon cancer.

Zhao Z, Feng Q, Yin Z, et al. Red and processed meat consumption and colorectal cancer risk: a systematic review and meta-analysis. Oncotarget. 2017;8(47).

Reynolds S. Pattern of DNA Damage Links Colorectal Cancer and Diet High in Red Meat. National Cancer Institute. July 22, 2021.

But does this mean that our weekly bacon, egg, and cheese sandwiches are driving the surge in colon cancer cases in the United States? Long story short: it’s unclear, as there are so many factors at play—but you definitely don’t want to overdo it with processed meats. 

 

“The adoption of westernized diets that are high in processed foods and low in fiber and essential nutrients, coupled with increasingly sedentary lifestyles, contributes to the rising rates of colon cancer worldwide,” Michelle Routhenstein, MS, RD, CDECS, CDN, a registered dietitian-nutritionist who specializes in cardiometabolic health at Entirely Nourished, tells MDLinx. 

 

Here’s what we know about bacon’s links to colon cancer

 

In recent years, more and more studies have found that people who regularly eat large amounts of processed meats, such as bacon, are at greater risk of developing colon cancer. 

An article published in March 2024 founds that people who ate more processed meat faced a 40% increased risk of developing colon cancer compared to those who ate smaller amounts of processed meat.

tern MC, Joel Sanchez Mendez, Kim AE, et al. Genome-Wide Gene–Environment Interaction Analyses to Understand the Relationship between Red Meat and Processed Meat Intake and Colorectal Cancer Risk. Cancer Epidemiology, Biomarkers & Prevention. January 17, 2024.

LeBlanc L. Large-scale study explores genetic link between colorectal cancer and meat intake. Newsroom. March 15, 2024.

Another report echoes findings that processed meat and gastric cancer appear to be intimately linked, and a meta-analysis evaluating 148 published articles connected processed meat consumption with an 18% increased colorectal cancer risk.

Kim SR, Kim K, Lee SA, et al. Effect of Red, Processed, and White Meat Consumption on the Risk of Gastric Cancer: An Overall and Dose–Response Meta-Analysis. Nutrients. 2019;11(4):826.

Farvid MS, Sidahmed E, Spence ND, et al. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies. European Journal of Epidemiology. 2021;36(9):937-951.

 

 

How much processed meat you eat is believed to influence your risk of developing colon cancer. According to the World Health Organization, one study found that every 50 grams, or 1.7 ounces, of processed meat eaten each day increases the risk of colorectal cancer by about 18%.

World Health Organization. Cancer: Carcinogenicity of the consumption of red meat and processed meat. October 26, 2015.

 

It’s important to note that the existing research has not proven that processed meats directly cause cancer but rather that there is a strong association between the two. “Although the data is not high-quality [enough] to prove this association, and they are mostly based on observational studies, there is enough data to suggest these associations possibly exist,” Pratima Dibba, MD, a board-certified gastroenterologist at Medical Offices of Manhattan, tells MDLinx.

Bacon, alone, is likely not driving the surge in new cases. Drinking high amounts of alcohol, smoking tobacco, being sedentary, and having diabetes—factors that are also becoming more common—can influence the risk of colon cancer as well. 

 

How might processed meats contribute to colon cancer?

 

Scientists have a few leading theories about why eating lots of bacon is linked to a higher risk of colon cancer. The meat contains nitrates and nitrites, preservatives used to boost shelf life and enhance taste.

Crowe W, Elliott CT, Green BD. Evaluating the Residual Nitrite Concentrations of Bacon in the United Kingdom. Foods. 2020;9)7):916.

While preservatives may make your breakfast treat tastier, they may also contribute to cancer, some scientists suspect. When certain nitrites are exposed to heat, as is the case when bacon is microwaved or pan-fried, they can produce compounds that damage our DNA, according to the National Cancer Institute.

Reynolds S. Pattern of DNA Damage Links Colorectal Cancer and Diet High in Red Meat. National Cancer Institute. July 22, 2021.

 

 

As a result, some nitrates have been labeled carcinogenic. “Processed meats are considered to be in the same risk category as alcohol, cigarettes, and asbestos regarding risks for cancer,” Dr. Dibba says.

 

So, how much bacon is too much?

 

The safest bet is to avoid eating processed meat every day. “It is thought that daily consumption of processed meats is the highest risk for cancers,”Dr. Dibba says. A study published in 2020 found that having as little as one slice of bacon every day may increase your risk.

Bradbury KE, Murphy N, Key TJ. Diet and colorectal cancer in UK Biobank: a prospective study. International Journal of Epidemiology. 2019;49(1).

That said, reducing your processed meat intake to 70 grams per week can help lower your risk, some data suggests.

 Aykan NF. Red meat and colorectal cancer. Oncology Reviews. 2015;9(1).

For reference, one slice of bacon is roughly 28 grams; a hot dog is about 50 grams. 

 

In general, Dr. Dibba recommends eating a diet rich in whole grains, fruits, vegetables, lean proteins, and grains.

 Hullings AG, Sinha R, Liao LM, et al. Whole grain and dietary fiber intake and risk of colorectal cancer in the NIH-AARP Diet and Health Study cohort.

According to Routhenstein, cruciferous vegetables, like broccoli, cauliflower, and Brussels sprouts, have anti-inflammatory and anti-cancer properties. Foods rich in fatty acids, like fish and walnuts, also appear to be beneficial, as they lower inflammation in the body.

Tu M, Wang W, Zhang G, et al. Ω-3 Polyunsaturated Fatty Acids on Colonic Inflammation and Colon Cancer: Roles of Lipid-Metabolizing Enzymes Involved. Nutrients. 2020;12(11):3301.  

“Research suggests that omega-3 fatty acids may also have protective effects against colon cancer by reducing inflammation and promoting healthy cell function,” says Routhenstein.