The recognition of dementia as a multifactorial disorder encourages the exploration of potentially modifiable risk factors. Social health might play a role in cognitive decline and dementia. The Social Health And REserve in the Dementia patient journey (SHARED) project aims to unravel the interplay between social health and biological and psychological factors on the trajectory from cognitive healthy. A multi-method approach is used, including the development of a conceptual framework for social health and its application in epidemiological and qualitative studies. Epidemiological studies in the SHARED project reveal potentially modifiable social health characteristics or markers associated with cognitive decline, dementia and mortality. This may shape new avenues for future interventions to prevent or delay cognitive decline and dementia and to enhance living well with dementia.