The Anti-Cancer Diet: Foods That May Prevent Cancer

According to the World Health Organization, cancer diagnosis rates are on the rise, with rates expected to double across the globe in the next quarter century. Though the risk of dying from cancer in the U.S. has steadily declined over the years thanks to medical advancements, there are still important steps that individuals can take to reduce the risk of developing cancer in their lifetime, including making cancer-fighting food choices.

What Are the Risk Factors for Developing Cancer?

Cancer does not have a single cause. Instead, many risk factors can contribute to cancer, including family history, genetic disorders, race, ethnicity, and exposure to certain viruses or environmental agents. While you can’t control many of these factors, you CAN control your lifestyle choices, including the foods you eat, which play a large role in determining cancer risk.

How Is Cancer Related to Diet? 

What we eat and drink can affect our health in a variety of ways, including the risk of developing cancer. The American Institute for Cancer Research (AICR) has developed several evidence-based, key recommendations for preventing cancer through lifestyle choices. They include increasing the amount of plants consumed, limiting certain foods, and enjoying physical activity.

Board-certified oncology nutrition specialist Amanda Mondini RD, LD, CSO, works with cancer patients at the Thompson Cancer Survival Center in Knoxville, Tennessee.

“Nutrition is a crucial factor when facing a cancer diagnosis,” Mondini says. “I have witnessed how malnutrition and incorrect nutrition information can negatively impact patients, and that motivates me to make myself accessible to as many of our patients as possible.”

What Kind of Diet Helps Prevent Cancer?

Mondini recommends avoiding “fad” diets in general. Some eating patterns, like the Mediterranean Diet and the Anti-Inflammatory Diet are more likely to be cancer-preventive simply because of the foods they emphasize. Both diets put a high priority on plant intake such as fruits, vegetables, whole grains, and beans. They promote lower consumption of foods like red and processed meats, which have been linked to increased risk of cancer.

What Are the Best Cancer-Fighting Foods?

Many experts encourage a plant-based diet for reducing cancer risk. Plants are an excellent source of phytochemicals, which are natural substances that can protect cells from being damaged. Damaged cells are more likely to lead to cancer development.

But you don’t have to be vegetarian or vegan to increase your plant intake. A helpful way to increase your plant consumption is by following the AICR’s model of eating, called the “New American Plate.”

For the New American Plate, vegetables, fruits, whole grains, and beans make up two-thirds (or more) of each meal, and animal protein makes up one-third (or less) of the same meal. It’s important to note that some plant foods have greater value in fighting cancer than others. For example, filling up two-thirds of your plate with white rice will not have the same effect as filling up two-thirds of your plate with asparagus, carrots, and brown rice (which contains fiber).

Some of the best cancer-fighting foods include:

• Fruits and Vegetables
  • In addition to phytochemicals, fruits and vegetables are rich in dietary fiber, which reduces the risk of colorectal cancer.
• Lean Proteins
  • We often think of proteins as animal-based, but plant-based proteins such as beans, legumes, and nuts can be a healthier option for cancer prevention.
• Whole Grains
  • Like fruits and vegetables, whole grains also contain dietary fiber, which helps keep the digestive tract healthy.

If increasing your plant intake sounds a little daunting, it’s OK to take it one step at a time. Mondini uses “SMART” goals with her patients. “Goals must be specific, measurable, attainable, relevant, and time-bound, meaning there is a deadline or timeline of progress milestones,” she explains. “Each patient’s goals will look different since no two patient scenarios are alike.”

If your goal is to increase vegetables or other plant consumption, you could start gradually by snacking on them or finding new recipes to complement their specific flavor profile.

Mondini says, “I used to dislike Brussels sprouts until I found this recipe. The balsamic glaze adds the perfect amount of sweetness to what can be a bitter vegetable. I love knowing that I am eating a vegetable that reduces my risk of mouth, esophageal, stomach, and colon cancers.”

When in doubt, the best way to determine a particular food item’s health value is to check the nutrition label. The information on the label describes calories, protein, nutrients and other food components, and can be very helpful in choosing healthier options.

What Foods Should We Avoid?

Mondini says, “I tell my patients food should not have morality ascribed to it. You are not ‘good’ or ‘bad’ for eating certain foods. However, some foods are not as helpful to us health-wise, and therefore it’s best to enjoy them in moderation.”

Foods to consider limiting include:

• Red meat (beef, pork, lamb)
  • The International Agency for Research on Cancer (IARC) classified red meat as a probable carcinogen (Group 2A) in 2015, based on data gathered from 800 studies. There is evidence that eating large amounts of red meat increases the risk of colorectal cancer.
  • One reason that red meat may contribute to cancer risk is that those who eat more red meat may tend to eat less of foods that can prevent cancer, such as fruits, vegetables, whole grains, and beans. The American Institute for Cancer Research recommends limiting red meat intake to 12-18 ounces per week.
  • “There can still be a place in our diets for red meat. Red meat is rich in protein and contains heme-iron, a type of iron that is most readily absorbed by the body,” Mondini says. But she says if you need to eat less and “reducing red meat consumption sounds like it will cramp your style, I suggest trying a meat substitute in one of your meals this week.”
• Processed meat (bacon, sausages, ham, salami, hot dogs)
  • In 2015, based on data from 800 studies, IARC classified processed meat as a human carcinogen (Group 1), meaning that there is enough evidence to conclude that it can cause cancer in humans. Some of the preservation methods used in producing processed meat, which include smoking, curing and salting, along with the addition of chemical preservatives, have been shown to cause cancer in laboratory studies.
• Sugar-sweetened beverages
  • Regular consumption of sugar-sweetened beverages can cause weight gain and obesity. Correlation with cancer risk is likely due to increased risk of being overweight or obese.
• Alcoholic beverages
  • Ethanol, the alcohol that is found in alcoholic beverages, is a human carcinogen.
  • When you drink alcohol and process ethanol, your body breaks it down into a chemical called acetaldehyde. Acetaldehyde not only damages your DNA, it also prevents your body from repairing the damage. Damage to your DNA can cause issues. DNA is your cells’ “instruction manual.” When your DNA is not working properly, your body’s cellular growth and function is affected — and cancer develops from out-of-control cell growth.
  • Alcohol may also reduce folate absorption or help potential carcinogens enter cells.

“Some of these foods alone have been shown to increase the risk of certain cancers,” Mondini says. “Others have been shown to increase the likelihood of weight gain, being overweight, and obesity. This is concerning because having excess body fat increases the risk of at least 12 cancers.”

While there is strong evidence that some foods may increase the risk of certain types of cancer, it’s important to note that there are many myths surrounding diet and cancer as well. Always consult your doctor or registered dietitian regarding any significant dietary changes or supplement use for cancer prevention or treatment.

Can Diet Cure Cancer?

While no diet can cure cancer, consuming certain plants and foods can help provide the nutrition your body needs to prevent or help ward off cancerous cells. If you do find yourself with a cancer diagnosis, Thompson Cancer Survival Center can help.

“Nutrition during treatment should not be scary,” Mondini says. “There is freedom in being able to redirect expectations, loosen restrictions, and quiet ‘the noise of food fear’ that patients experience.

“I’m glad that Thompson recognizes the impact dietitians can have on patient outcomes and quality of life, because not all cancer centers have dietitians on staff. It’s an honor to guide our patients the best I can in helping them achieve good nutrition status while managing the side effects of treatment.”

Thompson Cancer Survival Center treats many types of cancer and offers a special nurse navigation program to support patients on their treatment journey. For patients who are undergoing certain types of cancer treatments, Thompson experts also have provided nutrition tips for those undergoing radiation and nutrition tips for those undergoing chemotherapy.

Other Ways to Keep Cancer at Bay 

Besides diet, here are more steps you can take to lower your risk for cancer:

• Get recommended cancer screening tests as instructed by your healthcare provider. These help find cancer early when it’s easiest to treat. Screenings are available for breast, lung, cervical, and colorectal cancer.
• Stay at a healthy weight. Ask your provider for assistance in reaching your goal weight. A referral to a registered dietitian may be helpful.
• If you smoke, quit. Ask your healthcare provider for resources and support.
• Avoid or limit alcohol. It’s best not to drink, but if you choose to do so, females should limit themselves to one drink or less per day. Males should have two drinks or less per day.
• Protect your skin from the sun. Stay in the shade or wear broad-spectrum sunscreen that’s SPF 15 or higher. Don’t use indoor tanning.
• See your healthcare provider regularly. Talk with them about other steps you can take to lower your risk for cancer.

About the Author

Covenant Health

Headquartered in Knoxville, Tennessee, Covenant Health is a community-owned, healthcare enterprise committed to providing the right care at the right time and place. Covenant Health is the area’s largest employer and has more than 11,000 compassionate caregivers, expert clinicians, and dedicated employees and volunteers.