It is well known that ultra-processed foods are bad for health. But until recently, we didn’t know exactly why. Now there is growing evidence that chips, cookies, factory bread and prepared meats do not simply have poor nutritional value, but can cause harmful inflammation in the body, writes biochemist Richard Hoffman.
In European and North American countries, ultra-processed foods now account for more than half of the calories consumed. This is worrying as these foods have been linked to a number of health problems. For example, there is a greater risk of obesity and various chronic conditions such as cardiovascular disease and dementia.
In ultra-processed foods, various synthetic or industrial ingredients (such as emulsifiers, thickeners and artificial flavors) are combined into food products through a series of major manufacturing processes.
Sugary drinks and many breakfast cereals belong to the ultra-processed food group, as do more recent innovations. For example, there are the so-called “vegetable” burgers, which are usually made from protein isolates and other chemicals to make the products tasty.
The intense industrial processes used to produce ultra-processed foods destroy the natural structure of the ingredients. In this way, many useful nutrients such as fiber, vitamins and minerals disappear.
Recent research indicates that ultra-processed foods trigger inflammatory responses in the body because such foods are recognized as “foreign,” such as an invading bacteria.
It is well known that ultra-processed foods are harmful to our health. But it was unclear until recently whether this is simply because these foods have poor nutritional value. However, two recent studies show that this may not be enough to explain their health risks.
Health risks
The first study examined more than 20,000 healthy Italian adults. For example, it was found that participants who consumed the most ultra-processed foods had an increased risk of premature death from any cause. The second study, which surveyed more than 50,000 male health professionals in the US, found that high consumption of ultra-processed foods was linked to a greater risk of colon cancer.
What’s most interesting about these studies is that the health risks of an ultra-processed diet persisted even after taking into account the poor nutritional value of such a diet. This suggests that other factors contribute to the damage caused by ultra-processed foods.
It also means that getting the right nutrients elsewhere in the diet may not be enough to eliminate the risk of disease from eating ultra-processed foods. Also, attempts by the food industry to boost their nutritional value by adding a few extra vitamins can circumvent a more fundamental problem with these foods.
Inflammatory reactions
So what factors could explain why ultra-processed foods are so harmful to our health?
The Italian study found that certain inflammatory values — such as a higher white blood cell count — were higher in groups that ate ultra-processed foods most often. Our bodies can trigger an inflammatory response for various reasons, such as when we catch a cold or cut ourselves. The body responds by sending signals to our immune cells (such as white blood cells) to attack invading pathogens (such as bacteria or viruses).
Usually our inflammatory response goes away pretty quickly, but some people can develop chronic inflammation throughout their bodies. This can cause tissue damage and is linked to many chronic diseases, such as cancer and cardiovascular disease.
Many studies have shown that poor nutrition can stimulate inflammation in the body and that this is linked to a higher risk of chronic disease. The Italian study participants who ate ultra-processed foods most often also found more signs of inflammation. That suggests that inflammation may be one reason why ultra-processed foods increase the risk of disease. Some additives common in ultra-processed foods (such as emulsifiers and artificial sweeteners) also increase inflammation in the gut through changes in the microbiome (or the intestinal flora, red.) to cause.
Fast food fever
Some researchers have theorized that ultra-processed foods increase inflammation because they are recognized by the body as foreign, much like an invading bacteria. This causes the body to have an inflammatory response, also known as “fast food fever”. This increases inflammation throughout the body.
Although the US colon cancer study did not determine whether inflammation increased in the men who consumed the most ultra-processed foods, inflammation is strongly linked with an increased risk of colon cancer.
Research shows that other mechanisms – such as decreased kidney function and toxic substances in packaging – may also explain why ultra-processed foods cause so many dangerous health problems.
Prevention is better than cure
Since inflammatory reactions are trapped in our bodies, the best way to prevent this is to avoid eating ultra-processed foods at all. Some plant-based diets high 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 without 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.
Eating less ultra-processed foods can be a challenge. After all, these foods are designed to be highly palatable. Together with persuasive marketing, this can make resisting it very difficult 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. Usually things like emulsifiers, thickeners, protein isolates and other industrial-sounding products are a sign that it is an ultra-processed food.
And home-cooking with natural foods remains the best way to avoid damage from ultra-processed foods.
