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 bad for our health. But it has not been 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 its health risks.
The role of inflammation.
The first study, which looked at more than 20,000 healthy Italian adults, found that participants who ate 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 US male health professionals, found that high consumption of ultra-processed foods was associated with an increased risk of colon cancer.
What is most interesting about these studies is that the health risks of consuming a diet high in ultra-processed foods remained even after the poor nutritional quality of their diets had been taken into account. This suggests that other factors contribute to the damage caused by ultra-processed foods.
It also means that getting the right nutrients in other parts of the diet may not be enough to cancel out the risk of disease from eating 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 be sidestepping 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 various 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).
Usually our inflammatory response resolves fairly quickly, but some people can develop chronic inflammation throughout the body. This can cause tissue damage and is linked to 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 the Italian study participants who ate the most ultra-processed foods, this could suggest that inflammation may contribute to ultra-processed foods increasing 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, much like invading bacteria. The body then mounts an inflammatory response, which has been called “fast food rush.” This increases inflammation throughout the body as a result.
Although the US Colon Cancer Study did not establish whether inflammation was increased in men who ate the most ultra-processed foods, inflammation is strongly associated with 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 that are high in whole, natural foods (such as the Mediterranean diet) have also been shown to be anti-inflammatory. This may also explain why plant-based diets without ultra-processed foods can help prevent chronic disease. It is not currently known 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 very tasty, 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 food packaging. The best way to identify them is by looking at their ingredients. Usually, things like emulsifiers, thickeners, isolated proteins and other products that look industrial are a sign that it is an ultra-processed food. But preparing meals from scratch using natural foods is the best way to avoid the harm of ultra-processed foods.
Richard Hoffman is Associate Professor of Nutritional Biochemistry at the University of Hertfordshire.
The conversation
