About 60% of the calories in the average American’s diet come from highly processed foods. For decades we’ve learned that eating packaged products such as some breakfast cereals, snack bars, frozen meals, and nearly all packaged treats can lead to diabetes, obesity, and even cancer. I knew it was associated with undesirable health consequences, such as an increased risk of diabetes. cancer. But more recent research points to another major drawback of these often-tasty, always-convenient foods: They also seem to have a big impact on our minds.
Studies over the past decade or so have shown that the more ultra-processed foods people eat, the more likely they are to feel depressed and anxious. Several studies have suggested an association between UPF intake and an increased risk of cognitive decline.
What’s so insidious about these foods? How can you avoid the mental effects? Scientists are still working on the answers, but here’s what we know so far.
What are ultra-processed foods?
In 2009, Brazilian researchers examined foods from raw and minimally processed (fruits, vegetables, rice, flour, etc.) to processed (oils, butter, sugar, dairy products, some canned foods, smoked meat and fish). ) into four scales. ) and super machining. “Ultra-processed foods contain ingredients rarely used in homemade recipes, such as high fructose corn syrup, hydrogenated oils, protein isolates, colorings, artificial flavors, sweeteners, emulsifiers, preservatives and other chemical additives. Food Processing at the University of São Paulo, Brazil. This classification system is now widely used by nutritional researchers.
UPFs make up the majority of processed foods on the frozen food aisles of grocery stores and on fast food restaurant menus. 70% of processed foods sold in the United States are considered ultra-processed. They are removing more and more healthy foods from people’s diets and are widely consumed across socio-economic groups.
Dr. Eric M. Hecht, an epidemiologist at Florida Atlantic University Schmidt School of Medicine, said: “The problem is that manufacturers are making them less and less like real food in order to make their products taste better and better.”
What impact do ultra-processed foods have on mental health?
Recent studies have shown a link between highly processed foods and depressed mood. One 2022 study of more than 10,000 adults in the United States found that the more UPF participants ate, the more likely they were to report mild depression or anxiety. Those who consumed 60% or more from UPF had a significantly higher number of mentally unhealthy days,” said study author Dr. Hecht. “This is not proof of causation, but we can say that there appears to be a connection.”
A new study also reveals a relationship between high UPF intake and cognitive decline. His 2022 study, which followed nearly 11,000 Brazilian adults over his 10-year period, found a correlation between ultra-processed food consumption and reduced cognitive function (the ability to learn, remember, reason, and solve problems). It turns out that there is Professor Natalia Gómez Goncalves of the University of São Paulo said, “There is a natural decline in these abilities with age, but we found that this decline accelerated by 28% in people who consumed more than 20% of their calories from the UPF. ‘ said. Faculty of Medicine and lead author of the study.
Eating a healthy diet may offset the negative effects of eating ultra-processed foods. Dr. Goncalves found that following a healthy diet like the MIND Diet, which is rich in chicken, olive oil, significantly reduced the risk of dementia associated with the consumption of ultra-processed foods. “There was no association between UPF intake and cognitive decline,” said researchers who did not yet know what the safe amount of UPF is. added.
Why do ultra-processed foods have these effects?
Unknown. Melissa Lane, a researcher at Food & Mood, says, “Although many high-quality randomized studies have shown that a nutrient-rich diet has beneficial effects on depression, there is no evidence that the impact of food processing on mental health is significant. I don’t fully understand the role.” Center of Deakin University, Australia. However, there are some clues.
Much of the research has focused on the effects of poor gut health on the brain. Diets high in ultra-processed foods are typically low in fiber, found primarily in plant-based foods such as whole grains, fruits, vegetables, nuts, and seeds. increase. Dietary fiber is also necessary for the production of short-chain fatty acids, which are produced when broken down in the digestive system and play an important role in brain function, says Wolfgang, president of the International Society for Nutritional Psychiatry. Marx said. Senior Research Fellow at Deakin University. “We know that people with depression and other psychiatric disorders have less diversity in their gut microbiota composition and less short-chain fatty acids.”
Chemical additives in UPF can also affect intestinal flora. “The emerging evidence, primarily from animal studies, but also from human data, includes isolated nutrients (such as fructose), artificial sweeteners (such as aspartame and saccharin), and emulsifiers (such as carboxymethylcellulose and polysorbate-80). ) can negatively affect the gut microbiome,” Dr. Marx said.
According to Dr. Lane, poor gut microbiota diversity and a diet high in sugar can contribute to chronic inflammation, which is associated with many mental and physical problems. “It’s thought that increased inflammation and its interaction with the brain drives the development of depression,” she said.
It’s also worth considering the possibility that the link between highly processed foods and mental health can go both ways. “Diet affects mood, but the opposite is also true,” says Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard TH Chan School of Public Health. “When we’re stressed, anxious, or depressed, we tend to eat unhealthy foods, especially ultra-processed foods that are high in sugar, fat, and chemical additives.”
How to recognize ultra-processed foods
The best way to identify ultra-processed foods is to read the product label. Whitney Linsenmeyer, an assistant professor of nutrition at St. Louis University in Missouri, says that “a long list of ingredients, especially those that you would never use in a home cook,” is a clue that a food is ultra-processed. The Academy of Nutrition and Dietetics. Chemical names, unpronounceable words, and hard-to-find items in kitchen cabinets are often signs that a food belongs to the ultra-processed category.
Instead of resorting to ultra-processed foods, you can use convenience foods to make cooking easier. Products such as canned beans, frozen vegetables, cooked brown rice, and canned fish are all shortcut ingredients that fit within the scope of a healthy diet, as long as there are no manufactured products on the ingredient list. , herbs, spices, salts, cooking oils, etc., it shows that processed foods are not inherently unhealthy.”