February 8, 2013
No Link Between Cancer And Work-Related Stress
Brett Smith for redOrbit.com - Your Universe Online
Work-related stress may give you a heart attack, cause a stroke, make you more likely to consume alcohol, facilitate overeating, strain your relationships, reduce hours of sleep, and shorten your lifespan, but it probably won´t give you cancer, according to a new research in the British Medical Journal (BMJ).
Stress has been shown to cause chronic inflammation, which can play a role in the onset of cancer. And while stress can lead to cancer-associated habits like alcohol consumption or cigarette smoking–very few studies have attempted to link stress directly to cancer risk.
To reach their conclusion, researchers from the Finnish Institute of Occupational Health (FIOH), the University College London (UCL), and the IPD-Work Consortium analyzed 12 studies that involved 116,000 participants aged 17 to 70, from across Europe.
The team ranked the amount of self-reported, psychological stress at work by using a measure called job strain. They effectively described job strain as four categories: “high strain job (high demands and low control), active job (high demands and high control), passive job (low demands and low control), and low strain job (low demands and high control).”
The researchers collected data on cancer events by obtaining information from national cancer, death, and hospitalization registries. Other factors, such as smoking, age, and weight, were also taken into consideration. Individuals with a body mass index (BMI) of under 15 or over 50 were excluded from the review.
After analyzing the data, the team found that about 5,800 out of the 116,000 (5 percent) participants developed some form of cancer in the approximately 12-year time span covered by the data. They were unable to uncover any evidence of a connection between job strain and cancer risk.
The authors of the review also suggested that their robust analysis showed many previous findings that connected cancer and stress were erroneous.
“Many of the previously reported associations (of varying directions and magnitudes) between work related stress and risk of cancer could have been influenced by chance, low power in some studies, different covariate adjustment, or residual confounding from possible unmeasured common causes of work stress and cancer,” they wrote.
Despite the confidence in their findings, the authors also admitted that the research review had some shortcomings.
“We cannot exclude the possibility that residual confounding, such as from low intake of dietary fiber, shift or night time work, or exposure to pesticides, noxious fumes, dusts, or solvents, has influenced our estimates, though it is unlikely that residual confounding would have masked a strong association between job strain and cancer,” the report said.
As a side note, the researchers did find a connection between stress levels and coronary disease, supporting the idea of stress being associated with chronic disease. They advised that reducing work stress would improve the overall well-being of the general population, but that it is unlikely to have a marked impact on cancer rates.