Can Your Diet Affect Your Cancer Risk?

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*Updated February 2021.

We can’t blame all cancers on genetics, cigarettes, and bad luck. There’s an undeniable connection between your risk for developing certain cancers and what you eat and drink. But, do “superfoods” have the power to prevent cancer? Can too many hotdogs and beers cause cancer?

To help make sense of it all, Lesley Klein, medical nutrition therapist and clinical dietitian at Sylvester Comprehensive Cancer Center, part of the University of Miami Health System, provides tips to reduce your lifetime risk for developing cancers.

Maintain a healthy weight.

“Studies have shown that obesity is strongly linked to cancer,” Klein says. According to the National Cancer Institute and the American Cancer Society, higher body fat increases the risk for a number of cancers, including gallbladder, bile duct, kidney, liver, pancreatic, post-menopausal breast, colon, and advanced prostate cancers.

Why does high body fat contribute to cancer risk? Inflammation. People who are obese have chronic inflammation throughout the body, which promotes tumor development.

“But, even if you are at your ideal body weight,” Klein says, “to help prevent cancer, it’s important to think of eating healthier all around.”

Eat an anti-inflammatory diet.

What’s in an anti-inflammatory diet? Every color in the rainbow.

If your plate is typically filled with only brown, tan, and white-colored foods, you’re not eating a variety of cancer-fighting vitamins and minerals. “Antioxidants, phytochemicals, and fiber come in every color,” Klein says. “Try consuming one of each color every day.”

Examples include:

  • red: tomatoes, beets, kidney beans, cherries
  • orange: turmeric, carrots, apricots, butternut squash, sweet potatoes
  • yellow: bell peppers, succotash, squash
  • green: kale, spinach, asparagus, broccoli, green tea, rosemary
  • purple and blue: blueberries, eggplant, plums
  • brown: cinnamon, mushrooms, whole grains, nuts
  • white and black: onion, garlic, dark chocolate, unsweetened coffee
What’s not in an anti-inflammatory diet? Loads of sugar and animal fats.

“Added sugars and animal-based proteins and fats cause inflammation—which we know can trigger cancer growth,” she says. “So cutting back on those is a good place to start.”

Sugars are added to most processed and packaged products like crackers, sauces, cereals, cookies, frozen meals, yogurt, and fast foods. Added sugars are also hiding in smoothies, sodas, energy drinks, blended coffee beverages, and fruit juices. So, pay attention to nutrition labels and choose no-added sugar or low-sugar options. If you miss the sweetness, try using dates or maple syrup. It will take time for your taste-buds to get used to unsweetened foods, but eventually, you’ll be free from cravings for super sugary foods and drinks.

“If you’re used to eating a lot of red meat, I don’t expect you to cut it out of your diet,” Klein says. “Try limiting your intake to about 18 ounces a week. That way, you’ll be choosing fish, poultry, and plant-based proteins to substitute some of those meat dishes.”

By eating fish like salmon instead of meat, you also benefit from increasing the amount of omega-3 fatty acids in your diet. “Evidence from clinical studies shows that omega-3s have anti-inflammatory properties,” she says.

Cheese, full-fat dairy milk, and fried foods are high in saturated fat, so limit these as much as you can.

To add variety and flavor to your diet, try more plant-based proteins and fats. These include chickpeas, lentils, beans, nuts, and nut butters, seeds (like flax, hemp, and chia), soybeans (called edamame), pea protein (found in non-dairy milk, powders, and meat alternative products), whole grains, avocados, olives, and olive oil.

What about alcohol?

Cancer research experts agree that drinking alcohol contributes to about 3.5% of cancer deaths in the United States. The connection between alcohol and cancer is most evident in breast, oral, and liver cancers.

The more you drink, the more you increase your cancer risk—but some risk remains even for light drinkers who consume only one alcoholic beverage per day.

The bottom line is alcohol is a carcinogen. It can directly damage your DNA leading to mutated cells, and can physically carry cancer-causing substances into your cells. In addition, too much alcohol can lead to low levels of Vitamin D and other nutrients, which play a role in lowering cancer risk.

Make healthier choices more often.

“Diets have a beginning and an end, so they don’t really work,” Klein says. Aim to make better choices more often and for the long term.

“Look at your habits. Are you sabotaging your own good intentions? Are you eating mindlessly in front of a screen or quickly in your car? Do you mistake being thirsty or tired for hunger? Do you wait until you’re starving and can’t think straight before deciding what to eat?

“Remember that there are no quick fixes. Don’t beat yourself up when you’re not eating perfectly. Just make a better decision for your next meal.”

Sylvester Comprehensive Cancer Center offers integrative nutrition services and monthly classes. To learn more, call 305-243-8885.


Dana Kantrowitz is a contributing writer for UMiami Health News.


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