Ultra-processed foods, including packaged snacks, frozen meals and sugary drinks, have been tied to a growing list of health problems. Now, a new study adds lung cancer to that list.
Researchers analyzed data from more than 100,000 adults enrolled in the U.S. Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. After an average of 12 years of follow-up, they found that people who ate the most ultra-processed foods were 41% more likely to be diagnosed with lung cancer than those who ate the least, even after accounting for smoking and overall diet quality.
The study, published in Thorax, also found that higher intake of these foods was linked to a 37% greater risk of non-small cell lung cancer and a 44% greater risk of small cell lung cancer.
Ultra-processed foods are industrially manufactured products that typically undergo multiple processing steps and contain additives or preservatives to improve taste, texture or shelf life. They often combine refined ingredients like white flour, sugars and fats with flavor enhancers or colorings. Common examples include lunch meats, soft drinks, instant noodles, packaged snacks, store-bought baked goods, soups, sauces and fast-food items like burgers and pizza.
Researchers emphasize that it’s not processing itself that’s inherently harmful. Many processed foods, like fortified cereals or products containing vegetable oils, can be part of a healthy diet. The concern with ultra-processed foods is that they often replace nutrient-rich whole foods and contribute excess salt, sugar and unhealthy fats.
“Over the past two decades, the consumption of ultra-processed foods has significantly increased worldwide,” the researchers wrote. “The rise in UPF consumption may have driven global increases in obesity, cardiovascular disease, metabolic disorders, cancer and mortality.”
While this was an observational study, meaning it cannot prove cause and effect, researchers believe several factors could be at play. A diet high in ultra-processed foods can displace healthier options like whole grains, fruits and vegetables, which are known to protect against cancer. Industrial processing may also introduce harmful compounds such as acrolein, a toxic chemical found in both some processed foods and cigarette smoke, and chemicals that can leach from food packaging.
The authors note that more research is needed to confirm these findings in different populations. But for now, the message is clear: limiting ultra-processed foods in favor of whole or minimally processed options could benefit more than just your waistline and may help reduce cancer risk.
This study was funded by the Chongqing University Cancer Hospital, along with grants from the Chongqing Talent Plan and the Chongqing Shapingba District Technological Innovation Project.