The data will allow researchers to look for early markers of disease in the brain, including dementia and cancer.
The UK Biobank project is a £43m study funded by Wellcome, the Medical Research Council and the British Heart Foundation. It aims to create a cohort of 100,000 participants with comprehensive brain and body imaging data.
These first 5,000 MRI scans represent just 5% of the data the researchers aim to collect by 2020.
By following subjects over time and linking the imaging results to detailed health and mortality data from the NHS and the Office for National Statistics, the researchers are building a valuable resource that can reveal subtle markers of disease risk.
Initial analysis of the data by University of Oxford and Imperial College London researchers has shown a number of associations. One association is between the integrity of the brain's white matter and cognitive function, and this appears to become stronger with age. This could help researchers to identify changes in white matter that may contribute to age-related cognitive decline.
The researchers found a pattern of strong associations between higher blood pressure and greater alcohol consumption that could reflect injury to connections in the brain.
The scans also reveal some more complicated patterns of correlation. For example, one pattern links brain imaging to intelligence, level of education, and a set of lifestyle factors that at first appear unrelated – including the amount of time spent outdoors and how much cheese people eat. It may be that, taken together, these factors create a profile of socio-economic-status and its relation to the brain.