We aim to quantitatively estimate the strength of the protective effect, if any, that attendance at religious services confers against cognitive and brain aging. Religion is known to be strongly associated with better health outcomes for elderly people but no study has yet determined the strength of the protective effect conferred by religion-i.e. whether religion can slow decline in mental and brain aging. We will take one to 3 year to analyze religion, cognitive, health and brain measures from a large cohort of individuals followed over time in the UK Biobank dataset in order to ascertain strength of the protective effect conferred by religion. If religion’s protective effect is significant support programs that assist in attending religious service for elderly who self-report as religious may help slow brain and cognitive aging for these individuals.