Well-Being Prevention & Cures

Ultraprocessed food intake linked with cognitive decline: study

Ultra-processed foods make up over half of all calories consumed by Americans.
Blurred image of processed food.

Story at a glance

  • Foods high in oils, fats and sugars that contain little or no whole foods have been linked with early death, higher cancer risks and obesity rates. 

  • New research shows eating more of these foods is also linked with faster rates of cognitive decline among middle-aged adults.

  • Eating less of these foods could help prevent dementia.

Eating more ultraprocessed food can increase the risks of colorectal cancer and premature death. However, new study results published on Monday show consuming more of these foods is also linked with higher rates of cognitive decline. 

That’s according to data from more than 10,000 individuals residing in Brazil. Over a median of eight years, adults who consumed the greatest amounts of overly processed foods (more than 20 percent of total daily calories) had a 28 percent faster rate of global cognitive decline and a 25 percent faster rate of executive function decline compared with those who ate less of the foods.

However, when the overall quality of participants’ diets was taken into account, the risk was eliminated. In other words, even if ultraprocessed foods made up more than 20 percent of an individual’s diet, if the rest of that person’s diet was of high quality, there was no association with cognitive decline. 

Researchers note the study findings underscore the importance of modifiable interventions to prevent cognitive decline, adding the prevalence of dementia is expected to reach 153 million cases in 2050. 

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In the past 40 years food supply industries have increased commercialization of ultra-processed foods, defined as “formulations of processed food substances (oils, fats, sugars, starch, and protein isolates) that contain little or no whole foods and typically include flavorings, colorings, emulsifiers, and other cosmetic additives,” authors wrote. Examples include ice cream, processed meats, and ready-to-eat frozen meals, among many others.

Although the research was carried out among a Brazilian population, consumption of ultra-processed food has been on the rise in the United States and may contribute to the country’s growing obesity epidemic and worsen chronic disease rates. Less than 60 percent of calories consumed by U.S. citizens come from ultraprocessed foods. 

The latest CDC figures classify 42 percent of American adults as obese, while around 74 percent are considered overweight. 

In the current study, the average participant age was 52. Fifty-five percent of participants were women and 53 percent were white. Those who reported extreme calorie intake were excluded from the study, as were individuals who took medication that could influence cognitive performance. 

The study was carried out between 2008 and 2017. Participants reported their food and drink consumption for the last 12 months using a questionnaire. They also completed cognitive tests up to three times every four years. 

Those who consumed the highest amounts of ultraprocessed foods tended to be younger, women, white, have a higher education level and income and a higher frequency of depressive symptoms. 

Several biological mechanisms could account for the relationship between consumption of ultraprocessed food and cognitive decline, including the influence of systemic inflammation caused by consumption of these foods. However, authors concluded more studies need to be carried out to better understand how the foods affect cognitive capabilities.