In the last 30 years we have learned an enormous amount about the risk factors for dementia and cognitive decline and whether they have their biggest impact in mid and/​or late life. Now we are starting to extend our understanding to earlier adult life and even childhood. To do this we are synthesizing the academic evidence using systematic review and meta-analysis techniques to deliver an overview of the current evidence at younger ages. We have recently published an article bringing together the available data on the impact of high blood pressure in childhood and early adulthood on cognitive function and are now looking at other modifiable risk factors that might be present in earlier life. This is important because the more we can understand about when and how the risk factors for poorer cognitive function have their impact, the better we can target our risk reduction strategies.