How ultra-processed food harms the body and brain…

Consuming ultra-processed foods that are typically high in salt, sugar, and fat—and cheap and accessible—may boost the risk of heart disease, diabetes, anxiety, depression, and cognitive decline.

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How ultra-processed food harms the body and brain
Consuming ultra-processed foods that are typically high in salt, sugar, and fat—and cheap and accessible—may boost the risk of heart disease, diabetes, anxiety, depression, and cognitive decline.

A large group of ultra-processed and fried foods including pizza, burgers, fries, onion rings, and hotdogs
Diets heavy in ultra-processed food are linked with increased morbidity and mortality, including increased risk for metabolic syndrome, obesity, and depression.
Photograph by wildpixel, Getty Images
ByJanis Jibrin
February 29, 2024
•
9 min read

Although many ultra-processed foods—soda, candy, energy bars, fruit-flavored yogurt, frozen pizza, and frozen meals—can satisfy cravings for sweet, fatty, salty foods, emerging research suggests these items are particularly bad for the heart and brain, with mood and cognition taking a hit.

The most recent meta-analysis looking at the impact of ultra-processed food, published in BMJ in February, found the most far-reaching and unsettling results. Researchers identified direct links between higher consumption of ultra-processed foods and a greater risk of heart disease-related deaths, type 2 diabetes, obesity, wheezing, anxiety, depression, sleep problems, and deaths from all causes.

These results are consistent with earlier studies. Diets high in these foods were linked to a 44 percent greater risk of depression and a 48 percent higher risk of anxiety, according to a meta-analysis published in the journal Nutrients. In one of these studies, risk rose from consuming just 33 percent of calories from ultra-processed food. A separate study from Brazil that tracked 10,775 people found that taking in just 20 percent of calories from these foods was linked to a 28 percent faster rate of cognitive decline compared with people who ate less processed food.

Also alarming is a study tracking about half a million people living in England, Scotland, and Wales that found the risk of dementia went up by 25 percent for every 10 percent increase in ultra-processed food.

“While the exact cause-and-effect relationship is still unknown, the strongest observational evidence from prospective studies leans towards the idea that eating high amounts of ultra-processed foods increases the risk of depression onset in the future,” lead researcher of the Nutrients article, Melissa M. Lane, wrote in an email. She is a post-doctoral research fellow at Deakin University’s School of Medicine, in Geelong, Australia.

It is common knowledge that eating too much salt, sugar, and/or saturated fat is linked to chronic inflammation, high blood pressure, high blood sugar, heart disease, and type 2 diabetes. What the public may not appreciate, however, is that all these conditions affect the brain by raising the risk for vascular dementia—which is decreased blood flow to the brain. Additives such as certain artificial sweeteners and monosodium glutamate may also interfere with the production and release of brain chemicals such as dopamine, norepinephrine, and serotonin, which can adversely affect mental and emotional well-being.

Another problem with ultra-processed foods is that they might be addictive. “Ultra-processed foods have more in common with a cigarette than foods by Mother Nature,” says Ashley Gearhardt, professor of psychology at the University of Michigan, Ann Arbor.

That’s by design; “Multi-billion-dollar companies create these foods to hook us, so our agency around food is low. I see this as a food sovereignty issue,” says Cindy Leung, assistant professor of public health nutrition at Harvard T.H. Chan School of Public Health, Boston.

Humans have evolved to respond to foods that are sweet, fatty, and high in calories. For most of human existence this helped us survive. But in nature, foods are only modestly high in sugar—like berries—or high in fat, like nuts.

“You don’t find foods high in both sugar and fat,” says Gearhardt. “That’s a hallmark of ultra-processed foods. Add in salt, artificial flavorings, and bright colors, and our brain simply loses control over these foods.”

Unprocessed vs. processed vs. ultra-processed
Processed foods can be healthy, it’s the ultra-processed items that are linked to poor health. What’s the difference? Very generally, ultra-processed foods use ingredients not found in a home kitchen. A more precise description comes from the NOVA classification system.

Unprocessed or minimally processed foods such as fresh or frozen fruit, vegetables, seafood, meats, flour, and pasta, usually have just one item on their ingredient lists.

Processed ingredients, such as vegetable oils, sugar, corn starch, are extracted directly from unprocessed foods.

Processed foods, such as bakery bread without preservatives, most cheeses, and tuna, beans or vegetables canned in salt and water have short ingredient lists with recognizable terms, and salt is the main preservative.

Ultra-processed foods include items such as soda, candy, cookies, cake, energy bars, fruit-flavored yogurt, meal replacement bars and shakes, hotdogs, many types of packaged breads and cereals, and frozen meals. They are often high in fat, sugar and/or sodium and typically enhanced with flavorings, dyes, artificial sweeteners and/or other additives. Ingredient lists can be long, like the 48 items in a Nutri-grain Soft Baked Strawberry Breakfast Bar.