Social health, social reserve and dementia

There is increasing recognition of social health being protective against disease, including age-related cognitive decline and dementia. Many concepts around social health, reserve and connectedness are imprecise and without agreed definitions. The mechanisms by which social health is protective are not well understood.

Several observational studies suggest that social participation and connectedness are protective against cognitive decline whereas loneliness is a risk factor for dementia. The possible mechanisms include effects on inflammatory process and immune function, reduced vascular disease risk, improved health behaviours, lower risk of depression, and increased cognitive reserve through cognitive stimulation and physical activity. Social networks have been shown to modify the relationship between Alzheimer's disease and cognitive impairment. The relationship of social networks is, however, reciprocal, with dementia leading to social loss, which in turn worsens cognitive decline. Social reserve is conceptualized as both brain processes underlying the ability and predisposition to form meaningful social ties, and their instantiation as an environmental resource in high-quality social networks.

Consistent definitions of social health-related terms will lead to better understanding of their determinants so that tailored interventions can be developed to increase social reserve and improve social health of an individual.