This paper examines the dynamic relationship between data, participation and value through an analysis of developments in Alzheimer’s disease research. Alzheimer’s disease has risen rapidly up national and international policy agendas, particularly in Europe and North America. Research funding and initiatives have proliferated, many of which emphasise the potential value associated with existing data sources. The paper argues that the potential of these initiatives lies not only in realising the value of data through circulation, exchange and recombination, but in restructuring of the relations of data production and use, notably through the extension and intensification of research participation. As Alzheimer’s research focuses away from clinical settings and symptomatic “people with dementia”, participants in existing research studies are re-imagined as potential participants in future research studies, as “people with data”. Building on analyses of the role of clinical labour in the production of biovalue, the paper argues that reworked relations of data re-use and re-production suggest the ongoing and repeated attachments between data and bodies involved in the production of value. It concludes that this raises questions related to the study of research participation, and requires revisiting discussions about the appropriate representation of research participant interests.