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 know that ultra-processed foods are harmful to our health. But it’s not clear if that’s just because these foods have low nutritional value. Now two new studies have shown that a poor diet may not be enough to explain their health risks. This suggests that other factors may be needed to fully explain their health risks.
The role of inflammation
The first study, which involved more than 20,000 healthy Italian adults, found that participants who ate the most ultra-processed foods had an increased risk of dying prematurely from any cause. . The second study, which looked at more than 50,000 male healthcare professionals in the United States, found that a high intake of ultra-processed foods was associated with an increased risk of colon cancer.
What’s most interesting about these studies is that the health risks of eating a diet high in ultra-processed foods remained even after taking into account 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 the right nutrients from elsewhere in the diet may not be enough to negate the risk of disease from eating ultra-processed foods. Likewise, the food industry’s attempts to improve the nutritional value of ultra-processed foods by adding a few extra vitamins could circumvent 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 body can trigger an inflammatory reaction 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 (like white blood cells) to attack any invading pathogens (like bacteria or viruses).
Usually our inflammatory response resolves fairly quickly, but some people can develop chronic inflammation throughout their body. It can damage tissue and is implicated in many chronic diseases, such as cancer and cardiovascular disease.
Numerous studies have shown that a poor diet can increase inflammation in the body and this is linked to a higher risk of chronic disease. Given that signs of inflammation were seen in Italian study participants who ate the most ultra-processed foods, this could suggest that inflammation may help explain why ultra-processed foods increase risk. of illness. Some common food additives in ultra-processed foods (such as emulsifiers and artificial sweeteners) also increase gut inflammation by causing changes in the gut microbiome.
Some researchers have speculated that ultra-processed foods increase inflammation because they’re recognized by the body as foreign — much like invading bacteria. Thus, the body triggers an inflammatory response, which has been dubbed “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 consuming 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 issues.
Since inflammatory responses are hardwired into our bodies, the best way to prevent this from happening is to not eat ultra-processed foods at all. Some plant-based diets high in natural, unprocessed foods (like the Mediterranean diet) have also been shown to be anti-inflammatory. It may also explain why plant-based diets without ultra-processed foods can help prevent chronic disease. It is currently unknown to what extent an anti-inflammatory diet can help counter the effects of ultra-processed foods.
Simply reducing your intake of ultra-processed foods can be a challenge. Ultra-processed foods are designed to be super-appetizing – and with persuasive marketing, that 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 to look at their ingredients. Typically, things like emulsifiers, thickeners, protein isolates, and other industrial-sounding stuff indicate it’s an ultra-processed food. But making meals from scratch using natural foods is the best way to avoid the harms of ultra-processed foods.
Richard Hoffman is Associate Lecturer in Nutritional Biochemistry at the University of Hertfordshire.