Dietary folate intake and its association with longitudinal changes in cognition function.

BACKGROUND & AIMS: Folate (vitamin B9) is an essential co-factor for one-carbon metabolism. Controversial evidence has emerged regarding the association between folate and cognitive performance. The aim of the study was to investigate the association between baseline dietary folate intake and cognitive decline in a population exposed to mandatory fortification during a median follow-up of 8 years. METHODS: Multicenter, prospective cohort study involving 15,105 public servants aged 35-74 years old, both sexes, from The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Baseline dietary intake was assessed by a Food Frequency Questionnaire (FFQ). Six cognitive tests were performed in the three waves to assess memory, executive function and global cognition. Linear mixed-effects models were used to assess the association between dietary folate intake at baseline and changes in cognition over time. RESULTS: Data from 11,276 participants were analyzed. The mean (SD) age was 51.7 (9) years, 50% were women, 63% were overweight/obese, and 56% had graduated from college or more. Overall dietary folate intake was not associated with cognitive decline; neither vitamin B12 intake was a modifier of this association. General dietary supplements and specifically multivitamins use did not affect these findings. Natural food folate group was associated with a slower rate of global cognitive decline (ß (95% CI): 0.001 (0.000; 0.002), P = 0.015). There was no association between fortified food group and cognition scores. CONCLUSION: Overall dietary folate intake was not associated with cognitive function in this Brazilian population. However, folate naturally occurring in food sources may slow global cognitive decline.

Association Between Consumption of Ultraprocessed Foods and Cognitive Decline.

Importance: Although consumption of ultraprocessed food has been linked to higher risk of cardiovascular disease, metabolic syndrome, and obesity, little is known about the association of consumption of ultraprocessed foods with cognitive decline. Objective: To investigate the association between ultraprocessed food consumption and cognitive decline in the Brazilian Longitudinal Study of Adult Health. Design, Setting, and Participants: This was a multicenter, prospective cohort study with 3 waves, approximately 4 years apart, from 2008 to 2017. Data were analyzed from December 2021 to May 2022. Participants were public servants aged 35 to 74 years old recruited in 6 Brazilian cities. Participants who, at baseline, had incomplete food frequency questionnaire, cognitive, or covariate data were excluded. Participants who reported extreme calorie intake (<600 kcal/day or >6000 kcal/day) and those taking medication that could negatively interfere with cognitive performance were also excluded. Exposures: Daily ultraprocessed food consumption as a percentage of total energy divided into quartiles. Main Outcomes and Measures: Changes in cognitive performance over time evaluated by the immediate and delayed word recall, word recognition, phonemic and semantic verbal fluency tests, and Trail-Making Test B version. Results: A total of 15 105 individuals were recruited and 4330 were excluded, leaving 10 775 participants whose data were analyzed. The mean (SD) age at the baseline was 51.6 (8.9) years, 5880 participants (54.6%) were women, 5723 (53.1%) were White, and 6106 (56.6%) had at least a college degree. During a median (range) follow-up of 8 (6-10) years, individuals with ultraprocessed food consumption above the first quartile showed a 28% faster rate of global cognitive decline (ß = -0.004; 95% CI, -0.006 to -0.001; P = .003) and a 25% faster rate of executive function decline (ß = -0.003, 95% CI, -0.005 to 0.000; P = .01) compared with those in the first quartile. Conclusions and Relevance: A higher percentage of daily energy consumption of ultraprocessed foods was associated with cognitive decline among adults from an ethnically diverse sample. These findings support current public health recommendations on limiting ultraprocessed food consumption because of their potential harm to cognitive function.