AbstractBackgroundStudies have suggested that mentally stimulating activities and a socially engaged lifestyle have protective effects for dementia prevention; however, it is unclear which activities are more beneficial. This study aimed to investigate the role of cognitive and social type of leisure activities in relation to dementia incidence over a 15‐year follow up.MethodsThe analytical sample was comprised of 8,205 participants aged 50 years and older from the English Longitudinal Study of Ageing, who joined the study at wave 1 (2002‐2003), or at waves 3 (2006‐2007), or 4 (2008‐2009). Dementia was ascertained at every wave up to wave 8 (2016‐2017). Leisure activities were grouped into 6 cognitive activities (e.g. attending art classes) and 7 social activities (e.g. meeting with friends). Cox proportional hazard regression models were used to estimate the hazard ratios (HR) of dementia in relation to engagement in cognitive and social type of leisure activities. The models were adjusted for sex, marital status, education, wealth, physical health and health behaviours. A sensitivity analysis was carried out for a sub‐sample of 5,056 participants with APOEe4 data.ResultsDuring the follow‐up period, 413 (mean age 74) participants developed dementia. We found that with every additional cognitive activity, the hazard of dementia decreased by 11% (HR 0.89, 95% CI 0.82‐0.97, p=0.013), while for every additional social activity the hazard of dementia decreased by 8% (HR 0.92, 95% CI 0.85‐0.99, p=0.035). The association between social activities and dementia was maintained even after additional adjustment for APOEe4 (HR 0.90, 95% CI 0.81‐0.99, p=0.047), but not the association with cognitive activities. Individual analyses for each leisure item showed a significant independent association for reading the newspaper (HR 0.79, 95% CI 0.64‐0.97, p=0.029), having hobbies (HR 0.74, 95% CI 0.58‐0.93, p=0.012), and being a member of sports clubs (HR 0.71, 95% CI 0.52‐0.97, p=0.033).ConclusionsEngagement in various cognitive and social type of leisure activities was found to be protective against dementia risk. Noticeable effects were observed for reading the newspaper, having hobbies and being a member of sports club. Interventions to engage adults in opportunities for cognitive and social leisure participation are warranted.