Study links ultra processed foods and lung cancer

An international team of researchers tracked the health and food habits of more than 100,000 US adults, with an average age of 63. 

After an average of 12 years the team identified 1706 cases of lung cancer. 

The food survey questionnaires revealed consumption of UPFs, including ice cream, fried foods, bread, cakes, pastries, salty snacks, breakfast cereals, instant noodles, soups, margarine, confectionery, soft drinks, sweetened fruit drinks, hamburgers, hot dogs, and pizza. 

The research team, led by academics in China, found that average UPF consumption was nearly three servings a day, but ranged from 0.5 to six. 

The three types of food that featured the most were lunch meat and soft drinks. 

People who consumed the highest amounts of UPFs were 41 per cent more likely to develop lung cancer compared with those who consumed the least amount, academics wrote in the journal Thorax.

They found an increased risk found for both non small cell lung cancer and small cell lung cancer. 

The authors said they did make adjustments to their findings based on whether or not people smoked but they did not make adjustments for smoking intensity, which may have an impact. 

They stressed that "causality cannot be determined" from their findings and the data should be interpreted with caution. 

"Although additional research in other populations and settings is warranted, these findings suggest the healthy benefits of limiting UPF," the authors said. 

"Limiting trends of UPF intake globally could contribute to reducing the burden of lung cancer."

Commenting on the study, Sam Hare, a chest radiologist at the Royal Free London NHS Trust, said: "A quarter of lung cancer cases occur in non-smokers so we do need research exploring whether other factors are associated with lung cancer.

"We also know immunity is linked to cancer biology so it is a good idea to do research into factors like diet," Professor Hare said.

"However, further work is needed to establish direct causation between UPFs and lung cancer, crucially, whilst the study does make some adjustments for smoking status, the amount of smoking is not factored in, which is known to be directly related to lung cancer development. 

"Dietary habits also change considerably over the course of such long-term studies, as such, it is difficult to directly conclude that lung cancer is related to the level of UPF consumption alone given it was only declared at the start of the study. 

Prof Hare added that evidence-based advancement in the early diagnosis of lung cancer in non-smokers was needed but "this study isn't quite able to give us the answers yet".

Australian Associated Press