Objective Modifiable risk factors for dementia were recently identified and compiled in a systematic review. The ‘Lifestyle for Brain Health’ (LIBRA) score, reflecting someone's potential for dementia prevention, was studied in a large longitudinal population‐based sample with respect to predicting cognitive change over an observation period of up to 16 years. Methods Lifestyle for Brain Health was calculated at baseline for 949 participants aged 50–81 years from the Maastricht Ageing Study. The predictive value of LIBRA for incident dementia and cognitive impairment was examined by using Cox proportional hazard models and by testing its relation with cognitive decline. Results Lifestyle for Brain Health predicted future risk of dementia, as well as risk of cognitive impairment. A one‐point increase in LIBRA score related to 19% higher risk for dementia and 9% higher risk for cognitive impairment. LIBRA predicted rate of decline in processing speed, but not memory or executive functioning. Conclusions Lifestyle for Brain Health (LIBRA) may help in identifying and monitoring risk status in dementia‐prevention programmes, by targeting modifiable, lifestyle‐related risk factors. Copyright © 2017 John Wiley & Sons, Ltd.