Long‐term dietary intervention adherence among individuals with elevated risk of dementia: The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER)

Background Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) is a multi‐center, randomized trial that showed beneficial effect on cognition with a multi‐domain lifestyle intervention including nutritional guidance. The aim here is to investigate how dietary changes are maintained after the active intervention period, and if baseline cognitive performance modifies the intervention effect. Method Individuals aged 60‐77 years and at risk of dementia were randomly allocated into intervention (n=631) or control (n=629) group for 2 years, with post‐intervention follow‐up visit at 5 and 7 years. Neuropsychological Test Battery was executed and a z‐score for global cognition calculated (14 tests). Three food records during the intervention and one at 7 years were used to calculate FINGER dietary adherence score based on national recommendations (9 goals, higher indicating better adherence). A linear mixed model was used to evaluate association between dietary change, group allocation and baseline cognition dichotomized at the median, adjusting for age, education, sex, study area, BMI, and total energy intake. Result Altogether 783 participated at the 7‐year visits. Better baseline cognition predicted 7‐year participation (p<0.01) and food record completion (p<0.01), which was lower than at earlier visits (73%; n=572). Dietary quality improved more in the intervention group compared with the control over the 7‐year period (p<0.01). Baseline cognitive function did not modify the intervention effect on diet during the first years of the study (p<0.05 for the intervention effect in both cognition groups at the 1 st and the 2 nd year, respectively). On longer term the interaction between baseline cognition and intervention group became significant (p=0.03 at the 7‐year follow‐up), and the intervention effect was especially seen with lower baseline cognition. Dietary quality declined only in the control group participants with lower baseline cognition. Conclusion The FINGER dietary intervention showed that beneficial dietary changes are achieved by older individuals and also maintained after the active intervention period. These results indicate that while dietary changes during the intervention are achieved regardless of baseline cognition, people with lower baseline cognition may benefit more in long term, because their dietary quality is more likely to worsen without an intervention.