Researchers studied over 1,200 people in Spain to understand how eating ultra-processed foods (like packaged snacks, sugary drinks, and pre-made meals) affects cancer risk. They found that people who ate the most ultra-processed foods had more than double the risk of developing throat cancer and about 50% higher risk of stomach cancer compared to those who ate the least. Interestingly, certain types of processed foods were more concerning than others—particularly processed dairy products and sweets. However, no link was found with pancreatic cancer. While these results are concerning, researchers emphasize that more studies are needed to fully understand this connection.
The Quick Take
- What they studied: Whether eating a lot of ultra-processed foods (packaged, pre-made foods with added chemicals and preservatives) increases the chances of getting cancer in the throat, stomach, or pancreas.
- Who participated: 1,218 people living in a Mediterranean area of Spain, including 766 people who had been diagnosed with throat, stomach, or pancreatic cancer, and 452 healthy people without cancer for comparison.
- Key finding: People who ate the most ultra-processed foods had 2.3 times higher risk of throat cancer and 1.6 times higher risk of stomach cancer compared to those who ate the least. Processed dairy products and sweets were especially risky for stomach cancer.
- What it means for you: Eating fewer ultra-processed foods may help lower your cancer risk, though this study shows connection, not definite cause-and-effect. This is one reason among many to choose fresh, whole foods when possible. Talk to your doctor about your personal cancer risk factors.
The Research Details
This was a case-control study, which means researchers compared two groups: people who had already been diagnosed with cancer (the cases) and people without cancer (the controls). They looked back at what these people had eaten over the five years before they were interviewed, using detailed food questionnaires that had been tested for accuracy.
Researchers used a system called NOVA to classify foods as ultra-processed. Ultra-processed foods are products that have been heavily manufactured and contain added ingredients like sugar, salt, oils, and chemicals to make them taste better, last longer, or look more appealing. Examples include packaged snacks, sugary cereals, soda, instant noodles, and frozen pre-made meals.
The researchers then used statistical methods to calculate how much higher the cancer risk was for people eating the most ultra-processed foods compared to those eating the least, while accounting for other factors that might affect cancer risk like smoking, alcohol use, and overall diet quality.
Case-control studies are useful for studying diseases like cancer that develop slowly over time. By comparing what people with cancer ate to what people without cancer ate, researchers can identify patterns that might increase risk. This approach is more practical than following people for decades to see who develops cancer.
This study has several strengths: it included a reasonably large number of participants, it looked at three different types of cancer, and it examined specific types of ultra-processed foods separately. However, the study relied on people remembering what they ate five years earlier, which can be inaccurate. The study was also conducted in one region of Spain, so results might not apply equally to all populations. Additionally, this study shows association (connection) but cannot prove that ultra-processed foods directly cause cancer.
What the Results Show
The main finding was clear: people who ate the most ultra-processed foods had significantly higher cancer risk. For throat cancer, those in the highest consumption group had 2.29 times the risk compared to the lowest consumption group. For stomach cancer, the highest consumers had 1.56 times the risk.
When researchers looked at specific types of ultra-processed foods, they found different patterns. For stomach cancer, processed dairy products (like processed cheese and yogurt drinks) showed the strongest link, with 2.10 times higher risk. Processed sweets and pastries also increased stomach cancer risk by 1.76 times. For throat cancer, ultra-processed drinks and pre-cooked meals were the main culprits.
Interestingly, pancreatic cancer showed no clear connection to ultra-processed food consumption, suggesting that different cancers may be affected differently by diet. This finding is important because it shows that the relationship between processed foods and cancer is specific to certain types of cancer, not a general effect.
The study revealed that not all ultra-processed foods carry the same risk. This is important because it suggests that certain ingredients or processing methods may be more harmful than others. The fact that processed dairy products were particularly linked to stomach cancer is noteworthy, as is the connection between sugary drinks and throat cancer. These secondary findings help point researchers toward which specific ingredients or additives might be most concerning.
This research builds on earlier studies showing that ultra-processed foods are linked to various health problems. Previous research has connected these foods to obesity, heart disease, and some cancers, but the specific connection to throat and stomach cancers had not been thoroughly studied. This study fills that gap and confirms what some earlier research suggested. The findings align with the general scientific consensus that whole, minimally processed foods are healthier than ultra-processed alternatives.
Several important limitations should be considered. First, the study relied on people remembering what they ate five years before being interviewed, which is prone to error. Second, the study was conducted only in Spain, so the results may not apply equally to people in other countries with different diets and food systems. Third, while the study shows that people with cancer ate more ultra-processed foods, it cannot prove that the foods caused the cancer—other factors could be involved. Finally, the study was observational, meaning researchers simply observed patterns rather than randomly assigning people to eat different diets and tracking outcomes.
The Bottom Line
Based on this research, it appears reasonable to reduce ultra-processed food consumption, particularly sugary drinks, processed sweets, and processed dairy products. However, this single study is not definitive proof. The recommendation would be: try to eat more whole, fresh foods and fewer packaged, processed items. This aligns with general nutrition advice from health organizations. Confidence level: Moderate—this is one study among many suggesting processed foods are less healthy.
Everyone should be interested in this research, but it’s especially relevant for people with family histories of throat or stomach cancer, people who currently eat a lot of processed foods, and anyone interested in cancer prevention. This research is less directly applicable to pancreatic cancer prevention based on these findings. People with existing health conditions should discuss dietary changes with their healthcare provider.
Cancer develops over many years, so you wouldn’t expect to see immediate health benefits from reducing processed foods. However, other benefits like improved energy, better digestion, and weight management might appear within weeks to months. For cancer risk reduction, think in terms of years and decades—the goal is long-term habit change.
Want to Apply This Research?
- Track daily ultra-processed food servings by category: drinks, sweets/pastries, processed dairy, and pre-cooked meals. Set a goal to reduce each category by 25% over one month, then continue tracking weekly.
- Replace one ultra-processed item daily with a whole food alternative: swap soda for water, packaged snacks for fresh fruit, processed cheese for whole cheese, or frozen meals for home-cooked options. Use the app to log the swap and track consistency.
- Weekly check-ins to review ultra-processed food consumption patterns, identify trigger situations (stress, convenience, habit), and celebrate successful substitutions. Monthly reviews to assess progress toward reducing overall processed food intake and identify categories needing more attention.
This research shows an association between ultra-processed food consumption and certain cancers but does not prove that these foods directly cause cancer. Cancer risk is influenced by many factors including genetics, smoking, alcohol use, physical activity, and overall diet quality. This information is for educational purposes and should not replace professional medical advice. If you have concerns about cancer risk or are experiencing symptoms, please consult with a qualified healthcare provider. Anyone considering significant dietary changes should discuss them with their doctor or a registered dietitian, especially if they have existing health conditions or take medications.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.