Cancer is the second-leading cause of death in the United States. It’s a scary diagnosis, and one that we all want to avoid.
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We know we shouldn’t smoke. We wear sunscreen. We get regular cancer screenings. And when things pop up on our social media feed claiming to be the be-all-end-all of cancer-preventing foods and supplements, we lean in for a closer look.
The problem is that searching out foods that prevent cancer is a rabbit hole of pseudo-scientific advice. You can easily get results that skew more Wild West than American Medical Association.
We talked with cancer dietitian Joseph Dowdell, RDN, LD, to help weed through the clutter and explain what a healthy anti-cancer diet looks like.
Can you reduce cancer risk with diet?
Let’s be really clear: There is no single food that will prevent cancer. And no single food will cause it, either.
That said, a healthy diet and lifestyle can play a big role in lowering your risk of some of the most common cancers.
“Healthy eating can help prevent many of the chronic conditions that increase your risk of cancer,” Dowdell says. “Genetics and other health conditions can impact cancer prevalence as well, but those are usually more out of our control. What you can more easily control are the foods you choose to fuel your body.”
According to the American Cancer Society, carrying excess weight or having obesity — a body mass index (BMI) greater than 30 — is a risk factor for many cancers, including:
- Breast cancer (among people who have gone through menopause).
- Colon and rectal cancer.
- Endometrial and uterine cancer.
- Gallbladder cancer.
- Kidney cancer.
- Liver cancer.
- Ovarian cancer.
- Pancreatic cancer.
- Prostate cancer.
- Stomach cancer.
- Thyroid cancer.
- Mouth, throat and esophageal cancers.
Keeping your weight at a heathy level can help protect you from these cancers and other chronic conditions.
Best foods to reduce your risk of cancer
When thinking about the “shoulds” and “shouldn’ts” of a healthy diet to minimize cancer risk, it’s not a matter of black and white.
“We shouldn’t be fearful of food,” Dowdell says. “Instead, take a step back, and look at the big picture. That will allow you to focus on the diet changes that will have the most impact.”
Some of the best nutrition for preventing cancer and for generally living healthy can be found in the Mediterranean diet, which emphasizes natural and plant-based foods. Think more fruits, vegetables, nuts and lean protein, and less red meat and pre-packaged foods.
Dowdell also offers these seven tips for keeping your weight in check and lowering your cancer risk.
1. Eat more fruits and veggies
“Eat the rainbow” is a good rule of thumb, according to the American Cancer Society. The pigment that gives fruits and vegetables their color has ingredients that may reduce cancer risk. Aim to eat at least three different colors of fruits and vegetables each day. For example:
- Red: Apples, tomatoes and red cabbage.
- Orange: Cantaloupe, carrots and oranges.
- Yellow: Bananas, lemon and pineapple.
- Green: Broccoli and leafy greens, like spinach, kale and collard greens.
- Blue/purple: Beets, grapes, blueberries and rhubarb.
“All those multicolored vitamins and minerals play an important role in cell health, keeping our body functioning at its peak levels,” says Dowdell.
Aim to make your plate about half fruits and veggies. Split the other half between whole grains and lean meats, fish or plant-based proteins.
2. Be thoughtful about sugar
When it comes to cancer, some view sugar as public enemy No. 1. There’s even a common saying that “sugar feeds cancer.” Sugar, in fact, feeds all our cells, but not all sugars are created equal.
“The problem isn’t foods with natural sugar, like fruits and grains. It’s the added sugars that can lead to obesity and heart disease. Those can increase your risk of cancer,” Dowdell says.
Of course, when considering the sugar in your diet, there are the usual suspects, like sugary beverages, candies and desserts. But added sugars can also be found in a lot of products that don’t scream “sugar rush.” Sneaky sources of sugar include:
- Granola bars.
- Salad dressings.
- Yogurt, especially fruit-flavored varieties.
Keep your added sugar content low to keep your weight in a healthy range and lower your cancer risk. The American Heart Association recommends no more than 24 grams of added sugar per day in women and people assigned female at birth (AFAB) and a max of 36 grams per day for men and people assigned male at birth (AMAB).
3. Consider vitamin D supplements
Low levels of vitamin D are associated with an increased risk of breast, colon and prostate cancer.
Very few foods are naturally high in vitamin D, though you may find that some products, including soy, almond and oak milk may be fortified with vitamin D.
Exposure to sunlight (while wearing your sunscreen!) can help increase your vitamin D, and some people benefit from supplements. Talk with your healthcare provider about whether vitamin D supplements would be right for you.
4. Eat fiber
Foods that are high in fiber make you feel fuller longer, keeping you from searching for a snack 10 minutes after finishing lunch. Research shows fiber-rich foods release the anti-appetite molecule acetate, which sends messages to the brain telling us that we’re full.
High-fiber diets are associated with a decreased risk of colon cancer. Also, because high-fiber foods can make you feel fuller, they’re an important addition to an anti-cancer diet by helping to manage your weight.
High-fiber foods include:
- Whole grain cereals.
- Beans and lentils.
5. Cut down on alcohol
Alcohol use is associated with an increased risk of esophageal, throat and breast cancers. People who consume high levels of beer specifically also have an increased risk of rectal cancer. People with alcohol use disorder have increased incidences of liver cancer.
If you are looking for help with alcohol use disorder, the Substance Abuse and Mental Health Services Administration (SAMHSA) offers a hotline, 24/7, 365 days a year. Call 1-800-662-HELP (4357).
6. Go easy on the salt
Avoid cured, smoked and nitrite-preserved foods, like sausages, deli meats and hot dogs. Studies show a high level of connection between stomach cancers and high consumption of salty foods.
7. Cut down on fat
Minimize your daily fat intake to, ideally, 25 to 30 grams of fat per day, to keep your weight in check.
It’s good to be picky about fats. You want to stick with unsaturated fats — look for the words monounsaturated and polyunsaturated. Examples of good fats include:
- Almonds (14 grams per ounce).
- Peanut butter (8 grams per tablespoon).
- Avocado (10 grams per half cup).
- Hummus (2 grams per tablespoon).
Can cancer be cured with diet?
There is no scientific evidence that proves any diet can treat cancer, but if you are living with cancer, a healthy diet can:
- Help your body repair itself and recover from treatment.
- Strengthen your immune system.
- Protect your healthy cells against environmental damage.
If you’re living with cancer, your doctor will be able to suggest the best eating pattern for you and your condition. They also will be able to discuss your treatment plan and how diet may affect your cancer. Being flexible with what you eat and how much you eat can help combat side effects, Dowdell says. While it’s important to focus on healthy foods, it’s also important to prevent malnutrition while you’re living with cancer.
Getting started on eating healthier
If your diet is currently more fast-food fodder than plant-based paradigm, that just means you need to work your way to a healthier eating pattern. You can do it!
Dowdell says to start small. “Making any change is difficult. But setting small, achievable goals makes big goals much easier to accomplish,” Dowdell says.
Remember that food can be an important part of life. People socialize over food. Sometimes we celebrate with food and strengthen our bonds with one another while cooking together. As you work to lower your cancer risk with a healthy diet, make your eating habits work as a part of your life.
“Food is powerful,” Dowdell says. “Some people use food for comfort. Others use food to be social. It’s important to still embrace those things but in the healthiest way possible. You can eat that piece of cake on your birthday or indulge a little during a barbecue. Having an occasional treat is perfectly fine. It’s when those practices happen daily that negative long-term effects come into play.”