For the study, 10,775 civil servants aged 35 to 74 years (mean age at baseline: 51.6 years, 53% white, 54.6% female) were recruited from six Brazilian cities and followed up in three waves about four years apart in the period from 2008 to 2017.
During a mean follow-up period of 8 years, individuals with ultra-processed food consumption above the first quartile showed a 28% faster rate of global cognitive decline (p = 0.003) and a 25% faster rate of executive function decline (p = 0.01) compared to individuals in the first quartile.
"Our findings are consistent with previous studies linking [ultra-processed food] consumption to adverse health consequences - such as increased risk of overweight and obesity, metabolic syndrome, cancer, cardiovascular disease and all-cause mortality," explained Natalia Gomes Gonçalves, Ph.D., and colleagues from the University of São Paulo Medical School in Brazil.2
In the large Framingham Heart Study, which has been ongoing for several decades, pro-inflammatory foods were also associated with brain ageing or reduced brain volume.
"These findings support current recommendations to limit the consumption of ultra-highly processed foods because they may impair cognitive function," the authors conclude.
This raises the question of how big the long-term effect might be, given that children and teens aged 2 to 19 years old met about two-thirds (67%) of their daily calorie intake with ultra-processed foods in 2018, according to the nationally representative, multi-year NHANES (National Health and Nutrition Examination Survey) Child Nutrition Study.