There is a well-established web of correlations between life expectancy, wealth, intelligence, education, and social status. It is challenging to pick apart the underlying mechanisms, however, given demographic and epidemiological data as a starting point. For example, a slow debate is presently underway regarding the degree to which the correlation between intelligence and life expectancy has genetic origins, in that more physically robust people tend to be more intelligent, versus the more obvious suggestion that intelligent people tend to take better care of their health. That low socioeconomic status correlates with an accelerated onset of age-related declines in health also has the look of being explicable through worse maintenance of health over the long term: the usual triad of diet and weight, exercise, and smoking. That said, this study controlled for smoking, which makes it more interesting than the usual such work.
Lower socioeconomic status (SES) is a determinant of many of the health problems that emerge at older ages. The extent to which lower SES is associated with faster decline in age-related functions and phenotypes independently of health conditions is less clear. This study demonstrates that lower SES (defined by wealth) is related to accelerated decline over 6 to 8 years in 16 outcomes from physical, sensory, physiological, cognitive, emotional, and social domains, independently of diagnosed health conditions, self-rated health, education, and other factors. It provides evidence for the pervasive role of social circumstances on core aging processes and suggests that less affluent sectors of society age more rapidly than more privileged groups.
Aging involves decline in a range of functional abilities and phenotypes, many of which are also associated with socioeconomic status (SES). Here we assessed whether lower SES is a determinant of the rate of decline over 8 years in six domains – physical capability, sensory function, physiological function, cognitive performance, emotional well-being, and social function – in a sample of 5,018 men and women aged 64.44 (standard deviation 8.49) years on average at baseline. Wealth was used as the marker of SES, and all analyses controlled for age, gender, ethnicity, educational attainment, and long-term health conditions.
Lower SES was associated with greater adverse changes in physical capability (grip strength, gait speed, and physical activity), sensory function (sight impairment), physiological function (plasma fibrinogen concentration and lung function), cognitive performance (memory, executive function, and processing speed), emotional well-being (enjoyment of life and depressive symptoms), and social function (organizational membership, number of close friends, volunteering, and cultural engagement). Effects were maintained when controlling statistically for other factors such as smoking, marital/partnership status, and self-rated health and were also present when analyses were limited to participants aged ≤75 years of age. We conclude that lower SES is related to accelerated aging across a broad range of functional abilities and phenotypes independently of the presence of health conditions and that social circumstances impinge on multiple aspects of aging.