The foods you choose not only govern energy levels and weight changes, but they can also increase or decrease your risk of colorectal cancer.
While studies have not yet shown that any food directly causes or protects against cancer, much research has shown correlations between diet and a higher incidence of colon cancer.
“The exact mechanisms by which our diet influences the development of colorectal cancer remain the focus of clinical and laboratory research,” he says. Jeremy Kortmansky, MDclinical director of the division of gastrointestinal medical oncology at Yale Cancer Center and Smilow Cancer Hospital. “However, it is well established that foods that cause inflammation lead to the recruitment of pro-inflammatory cytokines (a type of protein), which are associated with colorectal cancer.”
Dietary choices that promote inflammation can also affect the gut microbiome, a collection of microbes in the gastrointestinal tract, says Dr. Kortmansky. Unhealthy gut microorganisms create an environment in the colon where cancer can thrive, but a healthy gut can have a protective effect.
These are the five worst foods for colon health, according to experts, and what you can eat instead to reduce your risk of colon cancer.
1. beef
Beef and other red meats, such as veal, lamb, and pork, are considered some of the foods with the highest risk of developing colorectal cancer. In fact, studies have shown that with every 100 gram (g) increase [3.5 ounces (oz)] of red meat per day, the risk of colorectal cancer increases by up to 16 percent.Red meat contains a compound called heme iron, which can increase the formation of cancer-causing N-nitroso compounds.
Because of this increased risk, many doctors who treat colon cancer avoid red meat, including Suneel Kamath, MDgastrointestinal oncologist at Cleveland Clinic and assistant professor of medicine at Cleveland Clinic Lerner School of Medicine at Case Western Reserve University. “An unhealthy gut microbiome (more bad bacteria) has been associated with this type of diet,” he says. Between the health of your gut microbiome and the compounds red meat contains, long-term inclusion of this food in your diet may increase your risk of colorectal cancer.
2. Hot dogs and other processed meats
In 2015, the International Agency for Research on Cancer called processed meat carcinogenic to humans. “I rarely eat processed meats,” Kortmansky says. “These foods cause changes in the metabolites and microbiome of the gut.”
Beyond their effect on gut microbes, processed meats also contain chemical preservatives such as nitrates and nitrites, which can expose the colon to N-nitroso compounds and increase the risk of cancer growing there.
But added chemicals are not the only source of risk. Salted, cured, fermented or smoked meats can also increase the potential for cancer, says Dr. Kamath. Any processed meat can increase the risk of colorectal cancer by up to 22 percent for every 50 g (1.8 oz) consumed per day.
3. Charred steak
The way red meat is cooked can also affect cancer risk.“Cooking red meat at very high temperatures (such as on a barbecue) leads to the formation of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), chemicals that can damage DNA and lead to tumor development,” says Kortmansky.
Research has shown this connection in animals, but more research is needed in humans.
How you cook meat has an impact, but the meat itself is still 90 percent of the problem, says Kamath, who recommends avoiding red and processed meats no matter how they are cooked.
4. sweets
The sugar in candy and other sweets can create excellent conditions for cancer growth. “Sweets have a very high caloric load, but they don’t really keep you full for long,” says Kamath. “And a lot of times I find that the problem is that because you don’t feel full at all, you’re just going to continue eating the normal amount that you would have eaten otherwise.”
Sweet foods aren’t the only culprits for empty calories: High-sugar drinks like juices and sodas are, too. “Sugary drinks are associated with excess calories that lead to obesity,” says Kortmansky, and research shows that people who have higher amounts of body fat with obesity have a higher risk of developing cancer.
“Obesity can cause insulin resistance and high levels of circulating insulin growth factor,” says Kortmansky, which can promote rapid cell division and the creation of tumors.
5. Alcohol
Although alcoholic beverages are not food, it is important enough that our two experts wanted to include alcohol on this list. “Alcohol is associated with an increased risk of several types of cancer, including colorectal cancer,” Kortmansky says.
For every alcoholic drink you consume per day, your risk of colorectal cancer increases by 6 percent, and this number can increase to 52 percent when you have four drinks a day. When you drink alcohol, it changes your gut microbiome, suppressing protective enzymes and facilitating the growth of cancer cells, Kortmansky adds.
As the body digests alcohol, it produces acetaldehyde, which is a type 1 carcinogen, meaning studies have shown it can cause cancer in humans. Acetaldehyde can damage DNA, sometimes causing mutations, Kamath says. “We’re learning that there really is no safe amount of alcohol. Every drink you have has some negative impact,” he says.
What to eat instead
To reduce your risk of colorectal cancer, you can choose foods that protect you. “I’m a big proponent of the Mediterranean diet, which is very low in red meat and processed foods,” says Kamath. “Instead, their protein comes more from fish, poultry, beans and legumes.” Research reviews show that following a Mediterranean diet reduces the risk of colorectal cancer by up to 17 percent.
The Mediterranean diet also includes leafy green vegetables and cooking with olive oil instead of animal fat or other vegetable oils, Kamath says. “When you have this good diet, you also become enriched with better bacteria,” says Kamath.
The following foods may reduce your risk of colon cancer:
Cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, and cauliflower
Fiber, What you can get from whole grains, fruits and vegetables
Dairy Products such as milk, cheese and yogurt.
If you need help determining the best diet to reduce your risk of colon cancer, your healthcare provider can connect you with a dietitian to create an optimal nutrition plan with you.
The takeaway
Some types of foods can increase the risk of developing colon cancer, especially when consumed consistently and long term.
Colorectal cancer doctors recommend not consuming too much beef, processed meat, sugar-sweetened foods and beverages, and alcoholic beverages.
If you have questions about your personal risk of colorectal cancer, contact a healthcare provider, who can help you make safe nutritional decisions and reduce your risk.
