Here’s a breakdown of the provided text,focusing on the study’s findings and limitations:
Study Focus:
Objective: To investigate the association between the consumption of ultra-processed foods (UPFs) and the risk of developing lung cancer.
Participants: 101,732 individuals (50,187 men, 51,545 women) with an average age of 62. They completed a Food Frequency questionnaire at the start of the trials.
Timeframe:
Participant recruitment: november 1993 to July 2001.
Cancer diagnoses tracked: Until the end of 2009.
Cancer deaths tracked: Until the end of 2018. Average tracking period for the study: 12 years.
Food Categorization: Foods were classified into four groups:
1.Unprocessed or minimally processed.
2. Containing processed culinary ingredients.3. Processed.
4. Ultra-processed (UPFs).
Specific UPFs of Interest: sour cream, cream cheese, ice cream, frozen yogurt, fried foods, bread, baked goods, salted snacks, breakfast cereals, instant noodles, shop-bought soups and sauces, margarine, confectionery, soft drinks, sweetened fruit drinks, resturant/shop-bought hamburgers, hot dogs, and pizza.
Key UPF Consumption Data:
Average energy-adjusted UPF consumption: Nearly 3 servings/day (ranging from 0.5 to 6).
Most frequent UPFs consumed: Lunch meat (11%), diet or caffeinated soft drinks (just over 7%), and decaffeinated soft drinks (nearly 7%).
Key Findings:
Lung Cancer Diagnoses: During the study, 1706 new cases of lung cancer were diagnosed.
1473 cases (86%) were non-small cell lung cancer (NSCLC).
233 cases (14%) were small cell lung cancer (SCLC).
UPF Consumption and Lung Cancer:
Case numbers were higher in those who ate the most UPF compared to those who ate the least.
after adjusting for factors like smoking and overall diet quality, participants in the highest quarter of energy-adjusted UPF consumption were 41% more likely to be diagnosed with lung cancer than those in the lowest quarter.
Specifically, the highest UPF consumers were:
37% more likely to be diagnosed with NSCLC.
44% more likely to be diagnosed with SCLC.
Potential Explanations for the Association:
Low Nutritional Value: UPFs generally have low nutritional value.
High Sugar, salt, and Fat: UPFs often contain excessive amounts of sugar, salt, and fats.
Displacement of Healthy Foods: High UPF intake may displace healthier foods like whole grains, fruits, and vegetables, which are known to protect against cancer.
Altered Food Matrix: Industrial processing can alter the food matrix,affecting nutrient availability and absorption.
Harmful Contaminants: processing can generate harmful contaminants, such as acrolein (found in grilled sausages and caramel sweets, and also a component of cigarette smoke).
Packaging Materials: Packaging materials might also play a role.
Limitations of the Study:
Observational Study: This is an observational study, meaning it cannot establish cause and effect.
Smoking Intensity: Researchers could not factor in smoking intensity, which could be influential. Single Dietary Assessment: Dietary facts was collected only once, so it couldn’t account for changes in eating habits over time.
Small Number of Cancer Diagnoses: The number of cancer diagnoses was considered small.Conclusion and Future Directions:
The researchers highlight the need for confirmation of these findings by other large-scale longitudinal studies in different populations and settings.
They suggest that if causality is established, limiting global UPF intake could help reduce the burden of lung cancer.
They also note the critically important worldwide increase in UPF consumption over the past two decades and its potential role in driving global increases in obesity, cardiovascular disease, metabolic disorders, cancer, and mortality.
Source:
The study was published in the journal Thorax* by Wang, K., et al. (2025).
