Everybody knows too much stress and anxiety is bad for you. It dents the immune system, the cardiovascular system and may even contribute to cancer. Now it appears that one common source of stress -- our jobs -- could be having damaging effects on critical DNA in our cells. And that could lead to early aging, and the diseases and conditions that go along with it.
A study led by Kirsi Ahola of the Finnish Institute of Occupational Health measured the length of DNA sections called telomeres and how the lengths varied in association with job stress. It found that people with the most job stress tended to have shorter telomeres.
That matters because telomeres, located at the ends of chromosomes, serve as a kind of protective cap to the ropy strands, helping assure that the genetic instructions carried by genes on the chromosomes are accurately translated so cells get the right messages. Telomeres become shorter with age, oxidation and chemical insults. Often, when telomeres reach a critically short length, the cell dies in a process called apoptosis. Some cells don’t die. They become what scientists call “senescent.” They sputter along, making genetic errors and causing damage.
In their study, published this month in the journal PLoS One, Ahola and her co-workers looked at blood cells called leukocytes, a group of cells critical for immune function and a common subject of telomere experiments. They found that workers who experienced “severe exhaustion” from job stress had significantly shorter leukocyte telomeres than workers who were not exhausted from stress.
As a result, those workers could face the diseases of aging sooner than they might otherwise. Telomere shortening has been associated with Parkinson’s, type 2 diabetes, cardiovascular disease and cancer. In short, a constantly stressful job could make you old before your time.
“I think that these results should be used when considering health hazards and work place legislation,” Ahola told NBC News. “Chronic work stress can become a health risk and should be prevented.”
She acknowledged that “both individual and environmental factors affect the experience of stress,” so the same objective workplace conditions could have greater or lesser effects depending upon a number of personal traits.
That’s why, suggested Aoife O’Donovan, a research fellow at the University of California San Francisco, who studies the relationship between telomeres and stress, science can’t yet make definite cause and effect statements about telomere length, stress, aging and disease.
A number of life stressors aside from work, such as marital troubles, poverty, early childhood experience, gender (males tend to have shorter telomeres) -- as well as genetic makeup and health behaviors like smoking and diet – also appear to affect telomere length. For example, people who have experienced childhood trauma tend to be less able to cope with stress later in life and also tend to have shorter telomeres. The Finnish researchers adjusted their findings to take some of these factors into account, but it’s not possible to filter them out completely.
Still, O’Donovan doesn’t doubt the validity of the link between work stress and telomere shortening. “When you get a high enough dose of stress, hardly anyone is resilient,” she explained. “People can be resilient to one or two types of stressors in certain periods of time, but once it becomes cumulative, across domains, it’s rare to find resilient people.”
Stress builds on itself, she said. “Chronic stress begets chronic stress.”
But despite the ample evidence that stress is damaging, O’Donovan said, “It’s amazing how much we talk about it, and how little we’re are doing about it.”
Brian Alexander (www.BrianRAlexander.com) is co-author, with Larry Young PhD., of "The Chemistry Between Us: Love, Sex and the Science of Attraction," (www.TheChemistryBetweenUs.com) to be published Sept. 13.
More from TODAY Health: