Ultra-processed foods are combinations of various industrial ingredients (such as emulsifiers, thickeners, and artificial flavors), amalgamated into food products through a series of manufacturing processes.
Sugary drinks and many breakfast cereals are ultra-processed foods, as are newer innovations like so-called “plant-based” burgers, which are typically made with protein isolates and other chemicals to make the products pleasant to the taste
The intense industrial processes used to produce ultra-processed foods destroy the natural structure of food ingredients and remove many beneficial nutrients such as fiber, vitamins, minerals and phytochemicals.
Many of us are well aware that ultra-processed foods are harmful to our health. But it is not clear whether this is simply because these foods have low nutritional value. Now, two new studies have shown that poor nutrition may not be enough to explain its health risks. This suggests that other factors may be necessary to fully explain their health risks.
The role of inflammation
The first study, which examined more than 20,000 healthy Italian adults, found that participants who consumed the most ultra-processed foods had a higher risk of dying prematurely from any cause. The second study, which looked at more than 50,000 male health professionals in the United States, found that high consumption of ultra-processed foods was associated with an increased risk of colon cancer.
What’s interesting about these studies is that the health risks of eating a diet high in ultra-processed foods remained even after accounting for the poor nutritional quality of their diets. This suggests that other factors contribute to the damage caused by ultra-processed foods.
It also implies that getting adequate nutrients elsewhere in the diet may not be enough to cancel out the risk of disease from consuming ultra-processed foods. Similarly, the food industry’s attempts to improve the nutritional value of ultra-processed foods by adding a few more vitamins may avoid a more fundamental problem with these foods.
So what factors can explain why ultra-processed foods are so harmful to our health?
The Italian study found that inflammatory markers, such as higher white blood cell counts, were higher in the groups that ate the most ultra-processed foods. Our bodies can trigger an inflammatory response for a number of reasons, for example, if we catch a cold or cut ourselves. The body responds by sending signals to our immune cells (such as white blood cells) to attack any invading pathogens (such as bacteria or viruses).
Normally, our inflammatory response resolves fairly quickly, but some people can develop chronic inflammation throughout the body. This can cause tissue damage and is implicated in many chronic diseases, including cancer and cardiovascular disease.
Many studies have found that poor diets can increase inflammation in the body and that this is linked to an increased risk of chronic disease. Since signs of inflammation were seen in participants in the Italian study who ate the most ultra-processed foods, this could suggest that inflammation may contribute to why ultra-processed foods increase disease risk. Some common food additives in ultra-processed foods (such as emulsifiers and artificial sweeteners) also increase inflammation in the gut by causing changes in the gut microbiome.
Some researchers have theorized that ultra-processed foods increase inflammation because the body recognizes them as foreign, like an invading bacteria. Thus, the body generates an inflammatory response, which has been called “fast food fever”. This increases inflammation throughout the body as a result.
Although the US Colon Cancer Study did not establish whether inflammation increased in men who consumed the most ultra-processed foods, inflammation is strongly linked to an increased risk of colon cancer.
Research shows that other mechanisms, such as impaired kidney function and toxins in packaging, may also explain why ultra-processed foods cause so many dangerous health problems.
Since inflammatory responses are hardwired into our bodies, the best way to prevent this from happening is to not eat ultra-processed foods. Some plant-based diets rich in natural, unprocessed foods (such as the Mediterranean diet) have also been shown to be anti-inflammatory. This may also explain why plant-based diets free of ultra-processed foods can help prevent chronic disease. It is currently unknown to what extent an anti-inflammatory diet can help counteract the effects of ultra-processed foods.
Simply reducing your intake of ultra-processed foods can be challenging. Ultra-processed foods are designed to be hyper palatable, and coupled with persuasive marketing, this can make resisting them a huge challenge for some people.
These foods are also not labeled as such on the food packaging. The best way to identify them is by looking at their ingredients. Usually, things like emulsifiers, thickeners, protein isolates, and other industrial sleep products are a sign that it’s an ultra-processed food. But making meals from scratch with natural foods is the best way to avoid the damage of ultra-processed foods.
Richard Hoffman is Associate Professor of Nutritional Biochemistry at the University of Hertfordshire.
This article first appeared on The Conversation.