A new study finds that an individual's renting is more closely related to their rate of biological aging (how much their cells age regardless of their actual age) than being unemployed or a former smoker. The findings highlight the important link between housing and health and suggest that improving housing should be a focus of health interventions.
Housing is often cited as an important social determinant of health, and a lack of safe, secure, high-quality, affordable housing is associated with a range of adverse physical and mental health outcomes. But less is known about how the physical and psychosocial characteristics of housing affect health.
Researchers from the University of Adelaide in South Australia studied the impact of different housing-related factors on biological aging, which refers to the cumulative damage to the body's cells and indicates a person's intrinsic age rather than their actual age. For many diseases, biological age is an important risk factor: the older the cells, the more susceptible they are to disease.
While studying social survey data, the researchers also used DNA methylation to measure epigenetic information to understand whether there are pathways through which housing affects health. Epigenetics is the study of how behavior and environment cause changes that affect the way genes work, rather than changing the genetic code itself.
They obtained data from 1,420 respondents to the UK Household Longitudinal Study (UKHLS) and the British Household Panel Survey (BHPS) who provided blood samples containing methylation data. The researchers considered all possible housing elements in the data to reflect the complex role housing plays in people's lives. This includes physical factors (e.g. tenure, building type, availability of government financial support, urban or rural location) and psychosocial factors (e.g. housing costs, payment arrears, overcrowding).
When analyzing the data, the researchers took into account potentially influencing factors such as gender, nationality, education level, socioeconomic status, diet, accumulated stress, financial hardship, weight and smoking. Since chronological aging and biological aging occur simultaneously, this factor is also taken into account.
Researchers found that private renters age physiologically faster than those who own their homes outright (i.e. without a mortgage). The impact of private renting on aging is greater compared to unemployment and ex-smokers: almost twice as much as for the unemployed and 50% greater than for ex-smokers.
However, the researchers found that the effects of living in public housing on biological aging are no different than owning a home directly, because public housing costs less and provides greater security of tenure, even though such housing is often looked down upon by society.
When the researchers added housing history variables, being behind on housing or living in a house with pollution, dirt or other environmental issues was associated with faster rates of biological aging. To explain why historical debt experiences are associated with biological aging, but not contemporary debt experiences, the researchers suggest it has to do with repeated exposure to debt.
"Tenure and arrears played an important role in our analysis, highlighting the role of psychosocial factors linking housing to health through biological aging," the researchers said.
Importantly, the researchers note that epigenetic changes are reversible and their health effects can be avoided by changing housing policies.
"Increased support for housing costs and limits on increases in housing costs may protect people from housing arrears and their health consequences," the researchers said. "DNA methylation is reversible, suggesting that improving or changing conditions in people who biologically age more quickly could correct the situation, thereby mitigating or reversing the health effects."
The study was observational and therefore cannot determine cause and effect, and the researchers acknowledged its limitations, including that no contemporary housing variables were measured and that the DNA methylation data came only from white European respondents. However, they said their findings were relevant to housing and health issues outside the UK, particularly to countries with similar housing policies.
The study was published in the Journal of Epidemiology and Community Health.