Ultra-Processed Foods Linked to Increased Lung Cancer Risk

A recent study has established a concerning link between the consumption of ultra-processed foods (UPFs) and an increased risk of lung cancer. In both the United Kingdom and the United States, these foods account for over half of the average diet, comprising items like ready meals, fast food, and sugary beverages. The findings, published in the respiratory journal Thorax, suggest that limiting UPFs could help mitigate the global impact of lung cancer, which is currently the most prevalent cancer worldwide, according to the World Cancer Research Fund.

According to the study’s authors, there were approximately 2.2 million new cases of lung cancer and 1.8 million deaths attributed to the disease globally in 2020. The research builds on previous findings from a BMJ study conducted in 2024, which linked UPFs to a range of health issues including heart disease, type 2 diabetes, and adverse mental health outcomes.

Study Overview and Findings

The researchers analyzed data from the US Prostate, Lung, Colorectal and Ovarian Cancer Screening Trials, which involved 155,000 participants aged between 55 and 74. These individuals were randomly assigned to either a screening or comparison group from November 1993 to July 2001. Cancer diagnoses were tracked until the end of 2009, with cancer-related deaths monitored until 2018.

Of those studied, 101,732 participants (50,187 men and 51,545 women, with an average age of 62) completed dietary questionnaires upon entering the trials. Foods were categorized into four groups: unprocessed or minimally processed, processed culinary ingredients, processed, and ultra-processed. The most commonly consumed UPFs included sour cream, ice cream, frozen yoghurt, fried foods, and various types of soft drinks.

During the 12-year follow-up, the researchers identified 1,706 new cases of lung cancer, including 1,473 cases of non-small cell lung cancer (NSCLC) and 233 cases of small cell lung cancer (SCLC). The study revealed that participants who consumed the highest amounts of UPFs had a 41 percent greater likelihood of being diagnosed with lung cancer compared to those who consumed the least. Specifically, they were 37 percent more likely to be diagnosed with NSCLC and 44 percent more likely to develop SCLC.

While the study provides important insights, the researchers note that it remains observational, meaning they cannot definitively establish cause and effect. They acknowledged limitations such as the inability to factor in smoking intensity, which could influence results, and the single collection of dietary information, which does not account for dietary changes over time.

Health Implications and Recommendations

Despite these limitations, the researchers emphasize the low nutritional value of UPFs and their high content of salt, sugar, and fats. They suggest that the rise in UPF consumption may be contributing to global increases in obesity, cardiovascular disease, metabolic disorders, and cancer mortality. The study notes that industrial processing affects nutrient availability and absorption, potentially generating harmful contaminants such as acrolein, a toxic substance found in grilled meats and linked to cigarette smoke.

Rob Hobson, a nutritionist and author of Unprocess Your Family Life, commented on the study’s implications, stating, “You can’t say from this study that UPFs cause cancer as it’s observational, so we’re looking at associations, not direct effects. But it does strengthen the case for looking more closely at the food environment many people are living in, where UPFs are cheap, convenient, and heavily marketed.”

Hobson encourages small dietary shifts towards healthier options, recommending more home-cooked meals and increased consumption of whole foods such as vegetables, beans, and grains. He advises that understanding food choices is crucial for supporting long-term health rather than striving for perfection.

As awareness of health risks associated with UPFs continues to grow, individuals are encouraged to reconsider their dietary habits and the impact of convenience foods on their overall well-being.