'I'm an Oncology Dietitian and This Is the One Food I Never, Ever Eat'

If there were one (delicious!) menu item you could ban from your diet to prevent cancer, would you cut it?

Oncology dietitian Nichole Andrews, RD, sure would—after all, she knows too much. By day, she helps her patients choose foods that prevent, treat, or help them recover from cancer. So when she sits down for breakfast, lunch, or dinner, she takes her own advice.

“While genetics certainly play a role in cancer risk, lifestyle factors—especially diet—are believed to account for a significant portion of the risk,” she told Parade in an interview about the viral TikTok above, which has received more than 2.8 million views since June of this year. “What we eat can influence various biological processes like inflammation, hormone regulation, and DNA repair, all of which are key factors in cancer development.”

There’s no question that some foods are better than others despite them all sitting alongside one another on grocery store shelves. Those classified as carcinogens directly cause cancer, while others are proven to increase cancer risk....or miraculously, reduce it.

Andrews relies on data to guide her dietary decisions. Here’s how she navigates the evidence when eating.

Related: 'I'm an Oncologist and This Is the Dinner I Swear By for Cancer Prevention'

The One Food an Oncology Dietitian Never Eats

When you think of the worst foods for your health in the grocery aisles, your eyes may stop on Twinkies, sugary cereals, and artificial colors and sweeteners. “Personally,” Andrews says, “I avoid processed meats like bacon, ham, and sausages.” Why? There is strong evidence from human studies that they can cause cancer, particularly colorectal cancer, she explains.

While there are plenty of foods suspected to increase the risk of cancer, strong evidence of cancer causation is serious business—and a good reason to put down your hot dog. “Foods that cause cancer directly damage DNA and can initiate cancer development,” Andrews says. Unfortunately, breakfast meats and cookout staples are black sheep in this department: The International Agency for Research on Cancer (IARC) classifies processed meats as Group 1 carcinogens.

But what is it about these foods that are so harmful? Andrews says they are made with the preservatives nitrates and nitrites, which can form the cancer-causing compounds known as N-nitroso during cooking or digestion. What’s more, research shows that cooking these meats at high temperatures can also produce harmful compounds like heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are also linked to cancer development, Andrews points out.

Related: Here's What an Oncologist Snacks On, With Cancer Prevention in Mind

The Drink She Avoids

While notorious artificially sweetened drinks remain in Andrew’s regular repertoire, she doesn't drink acohol. “Even small amounts can increase the risk of several cancers, including breast, liver, esophageal, and colorectal cancers,” she says. The risk remains for teetotalers: The more you drink, the greater your risk of these cancers—and no amount is considered safe because, like processed meats, alcohol is carcinogenic, according to recent warnings from the World Health Organization .

Other Eating Rules She Follows

When Andrews says she looks out for foods that “promote conditions that make cancer development more likely,” she’s subtly calling out sugar, an ingredient that is not classified as carcinogenic, but is likely to be eaten in excess—and diets high in sugar can set eaters up for obesity, a well-known risk factor for breast, colon, and endometrial cancers.

According to the World Cancer Research Fund (WCRF) , lifestyle factors like diet, physical activity, and weight management could prevent up to 30-50% of all cancers. Diet alone contributes significantly to this percentage. Although genetic predispositions may elevate cancer risk, diet can influence the expression of these genes—and the same goes for other environmental factors like smoking, pollution, and radiation. The good news? “A healthy diet is a proactive way to mitigate some of the damage from these other factors,” Andrews says.

What a Cancer Prevention Diet Looks Like

What is a “healthy diet” when cancer prevention is the goal? Turns out it looks a lot like the diet dietitians have been promoting for years, that is, it’s rich in fruits, vegetables, whole grains, and lean proteins, and is low in processed foods, sugars, and unhealthy fats, Andrews says.

To fill her plate with the good stuff, she focuses on cruciferous vegetables like broccoli, cauliflower, and Brussels sprouts, which get a good rap for containing antitumor compounds , She also goes heavy on berries like blueberries and raspberries, both of which are rich in antioxidants that protect DNA from damage . And then there’s fatty fish like salmon, which contains the all-mighty omega-3 fatty acids known for their anti-inflammatory properties .

While it would be nice if there were one food you could plop on your plate for full protection, Andrew says even the greenest of green foods can't save you from cancer on their own. “No single food will prevent cancer,” she confirms. “It’s the overall dietary pattern and a healthy lifestyle, including regular physical activity and weight management, that have the most impact.”

Instead of prescribing a star ingredient, she prescribes moderation, balance, and variety, all of which will serve you well in reducing your cancer risk without significantly limiting your lifestyle.

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Related: A Huge New Study Finds One-Third of Cancer Deaths Can Be Attributed to This One Preventable Lifestyle Factor

Sources

• Nichole Andrews, RD , an oncology dietitian
• Red Meat and Processed Meat , IARC Monographs
• Childhood Cancer Awareness Month 2024 , World Health Organization
• No level of alcohol is safe for our health, World Health Organization
• Diet, Nutrition, Physical Activity and Cancer, World Cancer Research Fund
• An Escherichia coli Nissle 1917 missense mutant colonizes the streptomycin-treated mouse intestine better than the wild type but is not a better probiotic , Infect. Immun.
• Protective Role of Dietary Berries in Cancer, Antioxidants (Basel)
• Protective Effects of Omega-3 Fatty Acids in Cancer-Related Complications, Nutrients.