Money might be more important to our health than we thought, if the results of a new study are anything to go by. Researchers have found that financial hardship causes changes in epigenetic markers, which can result in premature ageing.

Multiple studies have shown an inverse correlation between premature mortality and income, but this new research might finally give us insight into why that link exists.

A team from the University of Georgia looked at 100 middle-aged African-American women living in the US to find out whether financial hardship had any impact on the age of their DNA. The study ranked the woman on income and controlled for factors that might have influenced their DNA such as education level, marital status, and childhood trauma.

"Due to the high unemployment and incarceration rates experienced by black men, economic survival of the family is often shouldered by black women," the researchers explained. "Middle age is frequently a very challenging period for these women as they must contend with the stress of supporting multiple generations of dependents with resources provided by one or more low income jobs."

The team used a method known as an 'epigenetic clock' to determine the women's DNA age. Epigenetics is a rapidly emerging field of biology, where scientists analyse the markers on top of our genomes that the body uses to turn on and off certain genes throughout our lives.

"This instrument may be viewed as a biological clock, given that it can be used to assess whether individuals are aging biologically at a pace that is faster or slower than their chronological age," the researchers explain.

Seventy-one epigenetic markers that control gene expression, known as CpG methylation sites, were analysed. These CpG sites that are strongly associated with chronological ageing and were used to help determine a woman's DNA age, which was then compared against their real age.

The implications of the results weren't good. "As expected, there was a strong inverse relationship between per capita income and financial pressure, and these two variables were strongly correlated with accelerated ageing," the researchers explained. "Sixty-eight percent of respondents with incomes less than $3,900 show accelerated ageing, whereas over 70 percent of individuals with incomes above $15,000 display decelerated ageing."

The researchers believe this might be due to financial pressure contributing to stress. Past research has shown that increased stress contributes to premature ageing and mortality, and can have a negative effect on the brain, but until now, the biological factors driving this link weren't known.

More research will need to be done to find out exactly how financial stress influences these epigenetic markers, as well as the extent of the link. In the meantime, let's just hope that scientists can find a way to turn off the ageing process sooner rather than later.  

The research has been published in Social Science & Medicine.