Study finds link between ultra-processed food and cognitive decline

The study tracked 10,000 Brazilians over a decade

A new study has linked ultraprocessed foods — like prepackaged soups, sauces, and ready-to-eat meals — to cognitive decline.

Previous studies have linked foods like hot dogs, french fries, soda, cookies, cakes and other pleasure foods to health conditions like obesity, heart and circulation problems, diabetes and cancer, but a recent study has added cognitive decline to that list.

CNN reports that the new study found that eating those foods may contribute to overall cognitive decline, including in parts of the brain that control executive function — in other words, the ability to process information and make decisions.

Ultraprocessed foods are defined by the study as "industrial formulations of food substances (oils, fats, sugars, starch, and protein isolates) that contain little or no whole foods and typically include flavorings, colourings, emulsifiers, and other cosmetic additives."

The study found that both men and women who ate the most ultraprocessed foods had a global cognitive decline rate 28 per cent faster than those who did not eat those foods. They also had a 25 per cent faster decline rate of their executive functions than their peers who did not eat ultraprocessed foods.

“While in need of further study and replication, the new results are quite compelling and emphasize the critical role for proper nutrition in preserving and promoting brain health and reducing risk for brain diseases as we get older,” Rudy Tanzi, professor of neurology at Harvard Medical School and director of the genetics and aging research unit at Massachusetts General Hospital in Boston, told CNN.

The study was presented on Monday at the 2022 Alzheimer's Association International Conference. It tracked 10,000 Brazilians over the course of a decade. Just over half the study's participants were women, white or college educated. The average age was 51.

According to the study, up to 25 to 30 per cent of total calorie intake in Brazil is from ultraprocessed foods.

In the US, that number is 58 per cent. In the UK it is about 57 per cent.

“People who consumed more than 20% of daily calories from processed foods had a 28% faster decline in global cognition and a 25% faster decline in executive functioning compared to people who ate less than 20%,” the study concluded.

For individuals who consume 2,000 calories a day, that would mean consuming 400 or more calories of ultraprocessed foods daily.

The study found that the people most likely to consume ultraprocessed foods were "younger, women, White, had higher education and income, and were more likely to have never smoked, and less likely to be current alcohol consumers."

The study suggested that people should spend more time cooking and preparing their own food.