In the US, ultra-processed food makes up over half of dietary energy consumption and continues to increase in popularity. Research into these food types and their specific ingredients has discovered a link between increased consumption and an increased risk of cancer, in addition to other chronic diseases such as obesity. Growing concern about these negative health impacts has led many to try to reduce the levels of these foods in their diet.
This article will explain what ultra-processed food is, its role in increasing the risk of cancer and other health problems, and some tips on how to cut back on ultra-processed food including how to read food labels to identify these foods.
Ultra-processed foods are defined as formulations of ingredients made from substances derived from food or produced synthetically. Almost all foods are processed in some way, for example, to preserve food. The NOVA scale is used to categorize foods based on their level of processing - with ultra-processed foods as the highest category. Foods defined as ultra-processed include carbonated soft drinks, packaged snacks, frozen ready meals, and processed meats.
The ingredients making up ultra-processed foods are derived from industrial processes where whole foods are fractionated into their components - such as sugars, oils, and fats - and then chemically processed and modified. Other components are then added to make the food palatable (such as emulsifiers, sweeteners, and artificial flavors) and long-lasting (such as additives and preservatives). These ingredients lack important nutrients, are high in unhealthy fats and salts, and contain excessive energy density, raising concerns about health impacts.
Ultra-processed foods are prevalent in modern diets, contributing around 60 percent of calorie intake by Americans. Factors leading to such high levels of consumption include:
Substantial evidence links ultra-processed foods to cancer. One study found that increasing the proportion of ultra-processed food in the diet increased the risk of cancer by 12 percent. In addition to increasing the probability of developing cancer, higher ultra-processed food consumption is also linked to higher rates of cancer-related mortality. Specific associations have been made for animal-based products and soft drinks (including artificially and sugar-sweetened options).
Specific types of cancer have a strong link to the consumption of ultra-processed foods. Multiple studies have found an association between increased ultra-processed food uptake and an increased risk of developing colorectal cancer in men, and one study showed that men at the highest level of consumption had a 29 percent higher risk of colorectal cancer. An increased risk of women developing breast cancer is also seen - particularly in estrogen receptor-positive breast cancers. One study showed a 10 percent increase in ultra-processed food intake, resulting in a 5 percent higher risk of developing breast cancer. Increased risk of gastrointestinal cancer development and higher mortality rates have also been linked to ultra-processed food consumption.
A high proportion of ultra-processed food in the diet leads to poorer dietary quality, this may result in a decrease in important aspects of the diet such as whole grains and fiber - both of which are associated with a decreased risk of colorectal cancer. Food processing can result in the production of contaminants, including trans fats and acrylamide. Trans fats have been associated with cancer risk, potentially through their effects on insulin resistance and inflammation. Acrylamide has been classified as a Class 2A carcinogen. It is metabolized in the body to form a product called glycidamide, which can mutate and damage DNA, resulting in an increased risk of cancer.
A higher risk of obesity is linked to increased consumption of ultra-processed foods. These foods contain high levels of sugar and fats (leading to increased calorie intake) but low levels of nutrients such as fiber (leading to increased body weight). They may also contain contaminants that can disrupt metabolism. In addition, ultra-processed foods are addictive, so leading to increased consumption and high-calorie intake. Obesity is further thought to increase the risk of cancer recurrence and increased mortality.
The gut microbiome is the ecosystem of microbes found in the digestive tract. The balance between different types of microbes is key to maintaining a healthy gut and has knock-on effects on whole-body health. Ultra-processed foods can affect the composition of the gut microbiota by increasing the levels of harmful microbes and decreasing protective microbes. This leads to an increased risk of diseases, such as cancer. Dietary fiber is thought to lower the risk of developing colorectal cancer. However, eating a diet high in ultra-processed foods leads to a reduction in fiber consumption, increasing the risk of colorectal cancer.
The immune system comprises immune cells that survey the body for foreign organisms, repair tissue, and destroy damaged cells, including cancerous cells. However, chronic inflammation (where the immune system is constantly activated) can increase the risk of cancer through increasing DNA mutations, promoting cell proliferation, and creating an environment favorable to tumor growth. Consumption of a diet high in ultra-processed foods is thought to exacerbate chronic inflammation. The trans fats and refined sugars found in these foods are particularly implicated in inflammation.
One of the allures of ultra-processed food is the speed at which you can cook it when time is limited. Meal-prepping for the week is a good way to get around this. Having pre-prepared meals ready to go in the fridge or freezer is just as quick and much more healthy. It also reduces the temptation to impulse purchase ready meals or other ultra-processed foods. When preparing food, focus on whole foods - look for ingredients listed on the back of products that you would be able to find in your kitchen, and avoid foods with long ingredient lists filled with unfamiliar additives.
Try to replace ultra-processed snacks with healthier alternatives. For example, replacing a sugary breakfast cereal with plain bran cereal or oats - you could add in fresh fruit if you would like some healthier sugar. Buying freshly baked bread - even if just from a supermarket - rather than mass-produced white bread will decrease the number of additives and preservatives that you are consuming. Processed snacks are tempting, but try fresh fruit and nuts for a healthier substitution - you might even find that they keep you satisfied for longer.
Foods are unlikely to state outright that they are made up of ultra-processed ingredients, so you will need to read the ingredient list to check. Long lists of ingredients are generally a bad sign. You should specifically look out for ingredients never or rarely used in the kitchen - such as hydrolyzed proteins, high-fructose corn syrup, hydrogenated oil, and casein. These ingredients will generally be found at the beginning/middle of the list. You should also look for additives - such as natural/artificial flavorings, monosodium glutamate, or some types of sweeteners. These ingredients will be found at the end of the list.
Ultra-processed foods are made up of ingredients that are derived from food or produced synthetically. There is a growing body of evidence implicating consumption of ultra-processed foods with increased cancer risk and other health conditions. The increased consumption of these foods has specifically been linked to colorectal cancer, breast cancer, and gastrointestinal cancer. It has also been linked to issues with obesity, reduced gut health, and inflammation - all of which may further increase the risk of developing cancers.
Many people are unaware of the risks and consume ultra-processed foods in high amounts due to their taste, how quick they are to cook, and how cheap they are. However, healthier alternatives are available, and implementing routines such as meal prepping and carefully checking ingredient lists will help you decrease the amount of ultra-processed food you eat.
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