Ultraprocessed foods (UPFs) may contribute to premature death and cognitive decline, suggest the findings of two separate studies from Brazil. These new studies add to the small but growing body of observational evidence linking higher intakes of UPFs with a range of adverse health outcomes, including cardiovascular disease, obesity, and some cancers.
Using national food consumption surveys, demographic and mortality data, and prior study analyses, the first study, which was published in the American Journal of Preventive Medicine in November, estimated that about 57,000 (10.5 percent) of the 541,160 deaths of people ages 30 to 69 in Brazil in 2019 could be attributed to UPFs. The researchers further estimated that reducing UPF consumption by 10 to 50 percent could reduce premature deaths by about 6,000 to 29,000 annually. Their findings “reinforce the recommendations of the Dietary Guidelines for the Brazilian Population, particularly avoiding the consumption of UPFs.”
The second study, in JAMA Neurology in December, included 10,775 Brazilians ages 35 to 74 who were followed for an average of eight years, during which time the researchers assessed their food intake and cognitive functions. Those who consumed 20 percent or more of their daily calories from UPFs experienced a faster decline in global cognitive functioning and specifically in executive functions than those who consumed less. Because this was an observational study—and one that had several methodological issues—it doesn’t prove that UPFs caused the observed declines; other factors not controlled for may have at least in part contributed. Still, the authors concluded that limiting UPFs, especially in middle age, may be of some value in preventing cognitive decline. Another study earlier in 2022 linked UPFs with increased dementia risk.
Researchers have proposed that UPFs may increase systemic inflammation as a possible mechanism to explain their potential adverse effects.
According to the researchers of the first study, Brazilians overall consume about 13 to 21 percent of their calories in the form of UPFs, but for about a quarter of adults there, they provide about 50 percent of calories. Americans fare even worse—an estimated 60 percent of our calories, on average, come from UPFs, which means any potential adverse effects from them would result in even worse health outcomes.
What exactly are UPFs? By one definition, they are ready-to-eat, packaged products with five or more ingredients, including sensory-enhancing additives, that have gone through a number of processes to combine and transform them. They include everything from processed meats (like hot dogs and chicken nuggets), margarine, jarred sauces, and frozen meals to most baked goods, chips, sweetened breakfast cereals, ice cream, and candies. Think of them as multi-ingredient industrial formulations that are no longer recognizable as their original plant or animal sources. In other words, they are types of foods that health experts have consistently advised for decades to limit or avoid.