How junk food may be feeding cancerous tumors

Junk food like potato chips, ice cream and ready-made meals have long been linked with a spate of health conditions, including cancers, heart disease and diabetes.

Now, a new study by University of South Florida Health and Tampa General Hospital Cancer Institute has revealed that these ultraprocessed foods may be fueling cancerous growths in the colon.

Scientists made the discovery after examining 81 cancerous colon tumors and surrounding tissue. The tumors contained a high number of lipids, fatty compounds produced when enzymes break down food, that are likely to inflame rather than heal a tumor.

Those lipids greatly outnumbered healthier ones that typically come from unprocessed foods rich in omega-3 fatty acids like avocados and olive oil. The resulting imbalance of the immune system is driving chronic inflammation of tumors, the study found.

Those results also suggest potential for new forms of treatment for colorectal tumors using natural products rich in omega-3 fatty acids in place of synthetic drugs. The approach, known as resolution medicine, encourages the phases of healing that follow inflammation such as clearance of infections and regrowth of tissue.

“Cancer is like a chronic wound that won’t heal,” said Dr. Timothy Yeatman, a surgical oncologist and professor at the University of South Florida and Tampa General Hospital’s Cancer Institute. “If your body is living off of daily ultraprocessed foods, its ability to heal that wound decreases due to the inflammation and suppression of the immune system that ultimately allows the cancer to grow.”

The researchers have been awarded a five-year, $3.1 million grant through the National Institutes of Health to continue their research. The new study is being published in Gut, an international journal on gastroenterology and hepatology.

Yeatman said the findings add new impetus to calls to lower the consumption of processed foods heavy in sugar, saturated fats, chemicals and seed oil like canola.

But he acknowledges that will be no easy transition. Almost every ingredients label includes chemicals, soybean oil, sugar or sugar replacements like high-fructose corn syrup.

Seed oils like canola, vegetable and sesame seed, which produce omega-6 fatty acids, are also widely used in food products. While not an issue in small quantities, research has shown most Americans have an unhealthy ratio of the fatty acids they produce.

“There is a problem in the U.S. where all the food that we eat are contaminated with these bad seed oils and sugar,” Yeatman said.

The tumor samples came from patients at Tampa General Hospital, which were frozen within 30 minutes of removal and transferred to the USF and TGH Cancer Institute’s Biobank.

Ganesh Halade, an associate professor in the USF Health Heart Institute in the Morsani College of Medicine, was able to analyze the tumors using spectrometry. The tests revealed that the makeup of fatty acids in plasma from the surrounding tissue was different from that in the tumors.

He stressed that diet is only one component of a healthy body and that sleep and exercise are also critical.

The next phase of research will focus on how much a healthier diet and higher consumption of foods rich in omega-3 fatty acids can promote faster recovery and lower inflammation.

“If we can control our immune cells then they can limit the tumor’s growth,” Halade said.