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Ultra-processed foods may increase ovarian, other cancer risks, study says

Ultra-processed foods such as hot dogs and frozen pizza may increase your risk of developing cancer, warn scientists. (Kajakiki/Getty Images)
4 min

LONDON — Ultra-processed foods such as breakfast cereals, frozen pizza, ready-to-eat meals and fizzy drinks may increase your risk of developing cancer — particularly ovarian or brain cancer, researchers say.

Many foods go through a moderate amount of processing — such as cheese, salted peanut butter, pasta sauce — but ultra-processed foods have more additives, artificial flavors, colors, sweeteners and preservatives. Typically they are subjected to processing methods to transform their taste, texture and appearance and can include hot dogs, doughnuts, boxed macaroni & cheese, muffins and flavored yogurts.

Researchers at Imperial College London’s School of Public Health assessed the diets of almost 200,000 middle-aged adults for a 10-year-period in the United Kingdom and found a “higher consumption of ultra-processed foods is associated with a greater risk of overall cancer and specifically ovarian and brain cancer.”

It was also associated with an increased risk of dying from cancer, they found.

What are ultra-processed foods? What should I eat instead?

The peer-reviewed study, published in the Lancet’s eClinicalMedicine journal Tuesday, was a collaboration with researchers from the International Agency for Research on Cancer (IARC), University of Sao Paulo and NOVA University Lisbon.

Of the 197,426 individuals, some 15,921 people developed cancer and 4,009 cancer-related deaths occurred.

“For every 10 percent increase in ultra-processed food in a person’s diet, there was an increased incidence of 2 percent for cancer overall, and a 19 percent increase for ovarian cancer specifically,” Imperial College London said in a statement. These links remained after adjusting for socio-economic factors such as smoking, physical activity and body mass index (BMI).

It’s unclear why there was a particularly high increased incidence in ovarian cancers — however, separate research has found an association between the disease and acrylamide, an industrial chemical formed during high-temperature cooking procedures.

“Some potentially cancer-causing agents such as some controversial food additives and chemical agents generated during processing may interfere with hormone effects and thereby affect hormone-related cancers such as ovarian cancer,” Eszter Vamos, lead senior author for the study, told The Washington Post by email Wednesday.

More studies are needed to determine the impact on women and children, she said, as the latter tend to be the “main consumers of ultra-processed foods.”

According to the American Cancer Society, ovarian cancer ranks fifth in cancer deaths among women in the United States — accounting for more deaths than any other cancer of the female reproductive system. The cancer mainly develops in older women and is more common in White than Black women, it said.

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Almost 60 percent of the calories that adults in the United States eat are from ultra-processed foods, which often have a poor nutritional value. They account for 25 to 50 percent of the calories consumed in many other countries, too, including England, Canada, France, Lebanon and Japan.

The observational study “cannot prove cause and effect” definitively, Vamos noted, showing only an association between the foods and increased cancer risks. However, the study argues, the findings nonetheless highlight the importance of considering food processing in diets.

“Ultra-processed foods are everywhere and highly marketed with cheap price and attractive packaging to promote consumption,” study author Kiara Chang said in a statement. “This shows our food environment needs urgent reform to protect the population.”

Chang called for better labeling and packaging of food to make clear to consumers the risks of their choices, as well as subsidies for freshly prepared foods to ensure they remain accessible, “nutritious and affordable options.”

Other studies have shown a link between ultra-processed foods and higher rates of obesity, hypertension, type 2 diabetes and colon cancer. A recent study of more than 22,000 people found that people who ate a lot of ultra-processed foods had a 19 percent higher likelihood of early death and a 32 percent higher risk of dying from heart disease, compared with people who ate few ultra-processed foods.

“There has been a global rise in ultra-processed foods, and these products increasingly replace traditional foods in our diet,” said Vamos. “Generally, high income countries have the highest levels of consumption, and the U.S. and the U.K. are leading consumers.”

Brazil has banned the marketing of ultra-processed foods in schools, while France and Canada have pushed to limit such foods in their national dietary guidelines.

The simple diet swap to help you lose weight and lower health risks

Panagiota Mitrou, director of research and innovation at World Cancer Research Fund, which helped fund the study, said by email Wednesday that the findings were “significant” and should encourage people to limit their fast food consumption and “other processed foods high in fat, starches or sugars.”

“For maximum benefit, we also recommend that you make whole grains, vegetables, fruit and pulses a major part of your usual diet,” she added.

Anahad O’Connor contributed to this report.

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