Ultra-Processed Foods Linked to Increased Lung Cancer Risk

A recent study has established a concerning link between ultra-processed foods (UPFs) and an increased risk of lung cancer. This research highlights that in both the UK and the US, more than half of the average diet is comprised of UPFs, which include ready meals, fast food, and sugary beverages. The study, published in the respiratory journal Thorax, follows a previous investigation by the BMJ in 2024, which identified UPFs as contributors to various health issues, including heart disease and type 2 diabetes.

According to the World Cancer Research Fund, lung cancer remains the most prevalent cancer globally, with an estimated 2.2 million new cases and 1.8 million deaths recorded in 2020. The researchers involved in the new study suggest that reducing the intake of UPFs could play a significant role in mitigating the global impact of lung cancer.

The study examined data from the US Prostate, Lung, Colorectal and Ovarian Cancer Screening Trials, involving approximately 155,000 participants aged between 55 and 74. Participants were randomly assigned to either a screening or comparison group between November 1993 and July 2001. Their cancer diagnoses were tracked until the end of 2009, while cancer-related deaths were monitored until the end of 2018. Out of those studied, 101,732 individuals provided dietary information, revealing critical insights into their food consumption.

Researchers categorized foods into four groups: unprocessed or minimally processed, processed culinary ingredients, processed, and ultra-processed. UPFs were specifically identified as foods high in preservatives and additives, such as sour cream, ice cream, frozen yoghurt, fried foods, and various sweetened beverages. Notably, lunch meats accounted for 11 percent of UPF consumption among participants, while diet and caffeinated soft drinks represented just over 7 percent each.

Over a 12-year tracking period, 1,706 new lung cancer cases were diagnosed among participants, including 1,473 cases of non-small cell lung cancer (NSCLC) and 233 of small cell lung cancer (SCLC). Those who consumed the highest amounts of UPFs were found to be 41 percent more likely to develop 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 be diagnosed with SCLC.

The observational nature of the study means that definitive conclusions about cause and effect cannot be drawn. Researchers acknowledged limitations, such as the inability to factor in smoking intensity and the collection of dietary information only at the outset of the trials. Despite these challenges, the researchers expressed concern about the nutritional inadequacies of UPFs, which typically contain excessive levels of salt, sugar, and unhealthy fats.

“The rise in UPF consumption may have driven global increases in obesity, cardiovascular disease, metabolic disorders, cancer, and mortality, as these foods are confirmed risk factors for such conditions,” the researchers noted. They also highlighted the potential dangers of industrial processing, which alters the food matrix, affects nutrient absorption, and can introduce harmful contaminants.

Rob Hobson, a nutritionist and author, emphasized the necessity of examining the food environment, where UPFs are often marketed as cheap and convenient options. “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,” he stated.

Hobson advocated for incremental changes in dietary habits rather than demonizing specific foods. He suggested that individuals could benefit from cooking more meals from scratch and increasing their intake of whole foods, such as vegetables, beans, and grains. “It’s not about being perfect; it’s about balance and understanding how your food choices could be supporting or undermining your long-term health,” he concluded.

As public health advocates continue to explore the implications of UPF consumption, this study serves as a reminder of the need for greater awareness regarding dietary choices and their potential impacts on health.