Experts already know that high consumption of ultra-processed foods is bad news for your health, and new research suggests these foods can raise risks for a major killer: lung cancer.

Besides the fact that ultra-processed foods are often high in salt, sugar and fat, people who consumed a lot of these foods also tended to avoid healthier, cancer-fighting fare, researchers noted.

“Low consumption of minimally processed foods like fruits, vegetables, fish and whole grains was linked to increased lung cancer risk,” noted a team led by Yongzhong Wu of Chongqing Cancer Hospital, in Chongqing, China.  

They published their findings July 29 in the journal Thorax.

Ultra-processed foods are made mostly from substances extracted from whole foods, like saturated fats, starches and added sugars. They also contain a wide variety of additives to make them more tasty, attractive and shelf-stable, including colors, emulsifiers, flavors and stabilizers.

Examples include packaged baked goods, sugary cereals, ready-to-eat or ready-to-heat products and deli cold cuts.

Consumption of ultra-processed foods has already been associated with 32 health problems, including heart disease, obesity, diabetes, some types of cancer and depression. 

The new study may add the leading cancer killer, lung cancer, to that list.

Wu's team looked at data from the US Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trials. 

The trials tracked cancer incidence and deaths between 1993 and 2018 for 155,000 older adults. About 102,000 of the participants filled out detailed dietary questionaires that categorized foods as: Unprocessed or minimally processed; containing processed culinary ingredients; processed; and ultra-processed.

When it came to ultra-processed foods, the researchers focused particularly on sour cream, as well as cream cheese, ice cream, frozen yogurt, fried foods, bread, baked goods, salted snacks, breakfast cereals, instant noodles, shop-bought soups and sauces, margarine, confectionery, soft drinks, sweetened fruit drinks, restaurant/shop-bought hamburgers, hot dogs and pizza.

On average, the American adults enrolled in the study consumed three servings of ultra-processed foods daily — most often lunch meats and sodas or diet sodas.

Over an average follow-up of 12 years,1,706 new cases of lung cancer were diagnosed, Wu’s group noted. 

Even after accounting for common lung cancer risk factors such as smoking and general poor dietary quality, folks who placed in the top 25% in terms of daily intake of ultra-processed foods were 41% more likely to develop lung cancer, the analysis showed.

Wu’s team stressed that this study was not designed to prove cause-and-effect, only that there seems to be a link between ultra-processed food intake and lung malignancies.

However, they note that as consumption of these foods rises, rates of intake of fresh, healthy fare also declines.

“These findings need to be confirmed by other large-scale longitudinal studies in different populations and settings,” the researchers said, but “If causality is established, limiting trends of UPF [ultra-processed foods] intake globally could contribute to reducing the burden of lung cancer.”