A lifestyle score in childhood and adolescence was positively associated with subsequently measured fluid intelligence in the DONALD cohort study

PURPOSE: Lifestyle scores which combine single factors such as diet, activity, or sleep duration showed associations with cognitive decline in adults. However, the role of a favourable lifestyle in younger age and the build-up of cognitive reserve is less clear, which is why we investigated longitudinal associations between a lifestyle score in childhood and adolescence and fluid intelligence obtained on average 6 years later. METHODS: In the DONALD cohort, a lifestyle score of 0 to 4 points including healthy diet and duration of moderate-to-vigorous physical activity, sedentary behaviour and sleep was repeatedly assessed in participants aged 5 and 19 years. Data on fluid intelligence were assessed via a German version of the culture fair intelligence test (CFT), using CFT 1-R in children 8.5 years of age or younger (n = 62) or CFT 20-R in participants older than 8.5 years (n = 192). Multivariable linear regression models were used to investigate prospective associations between the lifestyle score and the fluid intelligence score. RESULTS: Mean lifestyle score of all participants was 2.2 (0.7–4) points. A one-point increase in the lifestyle score was associated with a higher fluid intelligence score (4.8 points [0.3–7.3], p = 0.0343) for participants completing the CFT 20-R. Furthermore, each additional hour of sedentary behaviour was associated with a lower fluid intelligence score (− 3.0 points [− 5.7 to − 0.3], p = 0.0313). For younger participants (CFT 1-R), no association was found in any analysis (p > 0.05). CONCLUSION: A healthy lifestyle was positively associated with fluid intelligence, whereby sedentary behaviour itself seemed to play a prominent role. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00394-022-02921-z.