The impact of socioeconomic status and lifestyle on cognitive aging and brain health: results from the LIFE-Adult-Study

Dementia risk and changes in cognitive performance follow a social gradient, however, evidence on the respective role of socioeconomic status (SES) and lifestyle for cognitive performance is inconclusive. We investigated effects of SES and lifestyle (Lifestyle for Brain Health (LIBRA)-index) on cognitive performance and neuroimaging markers. We analyzed data from the registry-based LIFE-Adult-Study (n = 1,581; Mage = 63.6, SD = 10.1; 45.9% female). Multivariable regression models examined associations of SES and LIBRA with cognitive performance and MRI-derived hippocampal volume and white matter hyperintensities (WMH) at follow up, as well as changes in LIBRA from baseline to follow-up, controlling for relevant covariates and time between baseline and follow-up assessment (mean: 6.6 years). Higher SES was associated with better cognitive performance at follow-up (b = 0.12, 95% CI: 0.01, 0.24). No linear association was found between LIBRA and cognition, but higher squared LIBRA-scores predicted lower cognitive performance (b = –0.007, 95% CI: –0.01, –0.001). No significant interactions between SES and LIBRA were observed when investigating changes in cognitive performance. LIBRA scores worsened more strongly among participants with low SES (b = 0.12, 95% CI: 0.03, 0.20). Detrimental changes in LIBRA were linked to higher WMH volume at follow-up (b = 0.02, 95% CI: 0.003; 0.03), while no effects on hippocampal volume were detected. Low SES predicted negative change in cognitive performance, while lifestyle changes showed an effect only beyond a certain threshold. Although no interaction between SES and lifestyle was found when predicting changes in cognitive performance, higher LIBRA-scores among low-SES individuals highlights the need for targeted prevention. Effects of LIBRA on WMH volume supports white matter as a potential early marker of lifestyle-related brain health.