Ultra-Processed Foods Increase the Risk of Head and Neck Cancer and Esophageal Cancer

The effects of eating habits on health are frequently studied and have major public health importance. New research suggesting that ultra-processed food consumption may increase cancer risk makes an important contribution to this critical area of nutritional science.

Why Do We Process Food?

Humans have processed food for hundreds of thousands of years for the following reasons:

• Extending Storage Life: Processing prevents spoilage caused by microorganisms and extends shelf life.
• Increasing Nutritional Value: Methods such as cooking and fermentation can improve the digestibility and nutritional value of some foods.
• Removing Toxic Substances: Some foods naturally contain toxic compounds. Processing can make these substances harmless.
• Improving Taste and Appearance: Food processing is used to improve taste, texture and appearance.
• Convenience: Processed foods are generally easier to prepare and suitable for quick consumption.
• Food Safety: Processing is needed to remove pathogens and make food safe to eat.

Important milestones in the history of food processing include:

1. The Stone Age: The earliest examples date back about one million years to the Stone Age. People used stone tools to cut and process meat and gathered and prepared plants.
2. The Discovery of Fire: The discovery of fire, about 400,000-250,000 years ago, marked a turning point. Cooking allowed food to be stored longer, made it easier to digest and increased its nutritional value.
3. The Beginning of Agriculture: The advent of agriculture about 10,000 years ago was an important step. Grain processing and storage, breadmaking and the processing of other agricultural products became widespread.
4. Fermentation: Fermentation was used around 6000 BC, particularly for alcohol production and processing dairy products.
5. Canning: Nicolas Appert's invention of canning in the 19th century was an important milestone, allowing food to be stored for long periods without spoiling.
6. The Industrial Revolution: Food processing technologies developed rapidly with the Industrial Revolution. The 19th and 20th centuries brought major advances in processing, packaging and preservation.
7. The Cold Chain and Frozen Foods: Developments in refrigeration and freezing in the early 20th century transformed food processing and storage.

Minimal Processing and Ultra-Processing Have Very Different Effects

The degree of processing largely determines how the foods we consume affect health.

Minimally processed foods undergo only simple procedures such as cleaning, peeling or cutting. This largely preserves their natural structure and nutritional value. Fresh fruit, vegetables and whole grains fall into this category. Minimal processing maintains freshness and natural flavor and may also improve nutritional value and digestibility. Moderately processed foods undergo procedures intended to keep them fresh longer, improve flavor or make them more convenient. These include pasteurization, drying, deep-freezing, fermentation and vacuum packing.

In contrast, ultra-processed foods are characterized by the addition of various chemicals, such as additives, preservatives and flavor enhancers. This extends shelf life and makes the taste, texture or appearance appealing, but often reduces nutritional value and may adversely affect health. Ultra-processed foods are generally high in sugar, salt and saturated fat, which may increase the risk of various health problems, particularly obesity, heart disease and certain cancers.

A Recent Study and Striking Findings

According to recent research by Morales-Berstein and colleagues in the European Journal of Nutrition , high consumption of ultra-processed foods may be associated with the development of upper aerodigestive tract cancers, such as head and neck cancer and esophageal adenocarcinoma. The new findings suggest that obesity may not be the only factor behind the link between these foods and these cancers.

Many earlier studies of foods that generally have unhealthy nutritional profiles have linked ultra-processed foods with 34 different cancer types in terms of cancer development.

Study Methods and Results

In the new international study, researchers analyzed the dietary and lifestyle habits of 450 thousand adult patients over about 14 years. They sought to determine whether the association between ultra-processed food intake and head and neck cancer or esophageal adenocarcinoma could be explained by increased body fat.

The researchers found that a 10% increase in ultra-processed foods increased head and neck cancer risk by 23% and esophageal adenocarcinoma risk by 24%. However, increased body fat explained only a small part of the statistical association.

A mind map summarizing the article is shown below:

Commentary

It makes sense that several observational studies have associated ultra-processed foods with overweight and greater body fat. These foods are generally tasty, convenient and inexpensive, and often encourage large portions and excess calorie intake. What stands out here, however, is that body mass index and waist-to-hip ratio did not adequately explain the association between ultra-processed food intake and upper aerodigestive tract cancers.

This suggests that focusing only on weight-loss treatments, such as semaglutide, will not be enough to prevent these cancers associated with ultra-processed food consumption. Broader prevention strategies are therefore needed.

The researchers suggested other possible mechanisms. Additives such as emulsifiers and artificial sweeteners , previously associated with disease risk, together with contaminants from food packaging and manufacturing, may partly explain the link between ultra-processed foods and upper aerodigestive tract cancers.

Ultra-processed foods are clearly associated with many adverse health outcomes. It remains uncertain, however, whether they cause those outcomes or whether underlying factors, such as general health behaviors and socioeconomic circumstances, account for the association.

The researchers stressed the need for further studies to identify mechanisms that may contribute to the association of ultra-processed foods with head and neck cancer and esophageal adenocarcinoma.

This study adds to the growing evidence suggesting a link between ultra-processed foods and cancer risk. The association between high intake and increased upper aerodigestive tract cancer risk supports our advice to reduce cancer risk by eating a healthy diet rich in whole grains, vegetables, fruit and legumes.