Ultra-processed foods, which make up as much as half of the average diet, have been linked to an increased risk of lung cancer, according to new research.
Ultra-processed foods (UPFs) – including processed sauces, crisps, processed meats and many ready meals – have already been associated with more than 30 harmful health effects, such as heart disease, type 2 diabetes and shorter life expectancy.
Now a study published in the research journal Thorax has added lung cancer to the growing list of potential risks.
Lung cancer is one of the most common cancers worldwide, with more than 43,000 diagnoses each year in the UK alone, according to the NHS. The disease often shows no symptoms in its early stages, but warning signs can include breathlessness, coughing up blood and unexplained fatigue.
Researchers behind the study say reducing consumption of ultra-processed foods could help lower the risk of developing lung cancer.
The findings are based on dietary data from more than 101,000 participants, men and women with an average age of 62, who were surveyed about their eating habits. While there is no single strict definition of a UPF, the foods are typically mass-produced and contain added preservatives and additives designed to improve flavour, texture and appearance.
Examples identified in the study included ice cream, shop-bought sauces, sweets, soft drinks, and ready-made burgers and pizzas. Ultra-processed foods are also generally low in nutritional value and tend to be high in sugar, salt and saturated fat.
During the study period, 1,706 cases of lung cancer were recorded. Most of these, 1,473 cases, were non-small cell lung cancer, which usually develops more slowly. The remaining 233 cases were small cell lung cancer, a more aggressive form of the disease.
The researchers stressed that no definitive conclusions can be drawn, as the study was observational and did not account for other factors such as smoking habits, which remain the leading cause of lung cancer. However, they noted that the increasing dominance of ultra-processed foods in modern diets may be contributing to rising rates of “obesity, cardiovascular disease, metabolic disorders, cancer and mortality”.
Nutritionist Rob Hobson said people should focus on gradual improvements to their diet rather than blaming individual foods. However, he told The Independent that the findings highlight the need to examine the wider “food environment” in which people live.
He said ultra-processed foods are often cheap, widely available and heavily promoted, making them an easy default choice for many households, and suggested that tackling these structural issues could play a key role in improving long-term public health.
The study adds to growing evidence that cutting back on ultra-processed foods and opting for more fresh, minimally processed ingredients may help reduce the risk of serious illness.
