**International Study Suggests Link Between Ultra-Processed Foods and Lung Cancer Risk**
A new large-scale study has pointed to a significant association between the consumption of ultra-processed foods and an increased risk of lung cancer, sparking renewed debate over dietary habits and cancer prevention strategies. The investigation, carried out by an international cohort of researchers, monitored the health and eating patterns of over 100,000 adults in the United States for more than a decade, shedding light on a possible dietary factor influencing lung cancer beyond the well-known risk from smoking.
The cohort, mostly made up of adults averaging 63 years of age, were asked detailed questions about their food choices, focusing particularly on their intake of ultra-processed foods (UPFs). These are classified as industrial formulations that generally contain sugars, fats, salt, additives, and preservatives, but little, if any, whole food content. Food items surveyed ranged from obvious snack foods like crisps and chocolates, to everyday staples such as bread, breakfast cereals, margarine, and even packaged soups. Notably, soft drinks and lunch meats featured prominently in the diets of the highest consumers.
Within an average follow-up period of 12 years, the researchers recorded 1,706 new cases of lung cancer within the group. After analysing the dietary data, they found that individuals who consumed the highest quantities of UPFs—averaging up to six servings a day—were 41% more likely to develop lung cancer compared to those whose diets contained the least amount of UPFs. This elevated risk applied not just to one form of lung cancer but was observed in both non-small cell and small cell lung cancers.
The study, published in the medical journal *Thorax*, has underscored the complexity of cancer risk factors. Although the researchers adjusted their results to account for smoking status, they did not factor in the intensity of smoking over time, a variable closely linked to lung cancer development. This limitation, according to the study’s authors, means the findings should be interpreted with caution, and no direct cause-and-effect relationship can yet be drawn.
Academics involved in the study, led by a team in China, nonetheless suggest that a reduction in the consumption of ultra-processed foods may be beneficial for public health, not least in the ongoing fight against lung cancer. “Limiting trends of UPF intake globally could contribute to reducing the burden of lung cancer,” they wrote, urging further research in diverse populations to confirm and better understand these associations.
Their cautious approach has been echoed by independent experts. Professor Sam Hare, a consultant chest radiologist at the Royal Free London NHS Trust, emphasised the need for more nuanced research. “A quarter of lung cancer cases occur in non-smokers, so exploring other risk factors—including dietary patterns—is essential,” Professor Hare commented. However, he also highlighted that dietary habits can change significantly over a decade or more and that the study only assessed diet at a single point in time. “We need genuine evidence-based advancement in the early diagnosis of lung cancer in non-smokers, but this study isn’t quite able to give us the answers yet.”
This new research comes at a time of shifting patterns in both diet and smoking habits, particularly among younger people. In a separate recent study covering the UK, the rate of teenage smoking has dropped dramatically over the past fifty years—from 33% in 1974, down to just 12% by 2018. Yet the growing popularity of vaping poses additional challenges, as researchers believe teenagers who vape are far more likely to become cigarette smokers than those who abstain from both.
Experts advise caution before drawing sweeping conclusions. While the evidence from large cohort studies such as this one signals potential links between processed foods and cancer risk, confounding factors—such as overall lifestyle, physical activity, and the quantity and duration of smoking—remain difficult to untangle.
Nonetheless, the growing body of research pointing to the potential dangers of ultra-processed foods has heightened calls for individuals to consider more balanced, less processed diets. As scientists continue their search for more definitive answers, public health campaigners are expected to advocate for further research and, potentially, public policy interventions aimed at reducing UPF consumption across all age groups.
In summary, while smoking remains the dominant risk factor for lung cancer, this study adds to a wave of recent research emphasising that other variables—particularly diet—may also play a role. As the scientific community pursues more comprehensive investigations, the emerging message appears to support the broader movement towards healthier, less processed eating habits for overall well-being.