Avoiding foods linked with cancer risk is an important part of a healthy lifestyle to ward off disease. We asked two experts to provide insight on how specific foods can impact our risk.
As the second leading cause of death worldwide, cancer affects millions of lives each year. Experts believe that cancer is most likely a byproduct of a person’s genetics combined with external cancer-causing factors, and that a third of the most common cancers may be prevented by improved lifestyle habits like healthy eating and regular exercise alone. Focusing on eating health-boosting foods is a critical aspect of cancer prevention but avoiding cancer-promoting foods and drinks can be just as essential. Read on to find out which foods to avoid - and which have provided cause for concern but are still up for debate.
Recognized foods and beverages that are linked to cancer
Ultra-processed foods: These foods are significantly altered from their original state, undergoing multiple manufacturing processes while containing many ingredients. Food products like hot dogs, sugary cereals, canned soups, and candy are higher in harmful fat, added sugar, and salt, and often contain carcinogenic compounds that form due to heat treating during processing. Some of these foods also include additives like sodium nitrite and titanium dioxide which are linked with cancer.
Red meat and processed meat: One recent study found that increasing red meat intake by 50g per day over 5.7 years boosted colorectal cancer risk by 20% and breast cancer risk by 13%. An increase of 20g of processed meat per day was linked to a 16% increase in risk for colorectal cancer. When meat is cooked or grilled at high temperatures, toxic chemicals are formed that can increase the risk of cancer, and the high iron intake associated with consuming these meats may enhance the development of dangerous gene-mutating compounds in the body that lead to these cancers.
Sugary drinks: A large 2019 study found that drinking only 3.4 oz of a sugar sweetened drink per day increased the risk of overall cancer by 18% and breast cancer by 22%. Ingesting 3.4 oz of a 100% fruit juice drink was also associated with an increase in overall cancer risk by 12%. This may be explained by the fact that when consumed often and in large doses, sugary drinks contribute to weight gain and obesity, conditions that are well known to heighten cancer risk.
These foods and drinks have been suspected of enhancing cancer risk, but more research is still needed
Acrylamide in potato products: Acrylamide is a chemical used in the manufacturing process of plastics, paper, food packaging, and for the treatment of drinking water. It can also naturally occur in foods like potatoes, crackers, bread, and breakfast cereal that contain a special amino acid when heated to high temperatures. Animal studies have shown that acrylamide ingestion increases the risk of certain cancers, raising concern about its effect on humans. But it was found that humans and animals metabolize acrylamide differently, and so far no clear link has been found between human ingestion and cancer.
Very hot beverages: Drinking hot beverages above 140°F daily may be associated with a high risk of esophageal cancer, a recent study indicated. Consuming very hot liquid can damage the inner lining of the esophagus, causing the cells to keep regenerating which increases the chance that cancer cells could form. But there is doubt over whether a cause and effect relationship exists between cancer and hot liquid alone due to other risk factors present among the study population, such as alcohol drinking, smoking, and exposure to environmental toxins.
Artificial sweeteners: Concern over aspartame, a popular calorie-free sugar substitute, came to light when a 2006 study found that rats that were fed aspartame developed leukemia and lymphoma. While research seems to suggest that sweeteners can cause weight gain and blood glucose spikes, the overall evidence has yielded inconsistent results when it comes to cancer in humans, and as of yet no distinct associations have been found.
Soy: Soy has gotten some bad press for its high level of plant estrogen, phytoestrogen, that can either act as human estrogen or block estrogen in the body. Past studies have shown that soy may be protective against prostate cancer, gastrointestinal cancer in women, and breast cancer, but the exact effect soy has on a particular person may depend on several factors, and there was concern soy's phytoestrogen would promote cancer in some. Ethnic groups metabolize soy differently, and hormonal differences exist among premenopausal and postmenopausal women that may affect the body's reaction to soy. Also, the type of soy product consumed seems to matter.
So, do we need to worry about our soy intake? We asked Dr. Patricia Ford, Doctor of Public Health in Preventive Care and registered dietitian at Loma Linda University Medical Center, who often assures her patients that “soy foods are healthy and safe for the general population, as a moderate intake of soy in food form does not increase cancer growth.” However, she warns against taking soy supplements, which contain a much higher isoflavone concentration than food, until more research is complete.
The bottom line: what role can food play in lowering our risk for cancer?
“We are learning that our dietary choices are very important in preventing cardiometabolic disease and cancer, but there is great individual variability,” said Dr. Linda Gaudiani, President of Marin Endocrine Care and Research and Medical Director and Founder of the Braden Diabetes Center. “Probably the best advice is to build one’s diet on fresh, whole unprocessed foods and to choose a variety of vegetables, legumes, beans, fruits and whole grains, healthy fats in moderation and lean proteins. Maintaining a lean and normal body weight with healthy food choices and small to moderate portion sizes prevents the inflammatory effects of obesity which appear to increase cancer risk overall.“