Researchers studying sleeping patterns have found a link between irregular sleeping patterns and the development of cancer. The risk of developing cancer was found to be considerably higher for those with irregular sleep patterns than for those with regular sleep patterns. Scientists and health advocates have long been concerned about the damaging impact of shift work on health. The report stated, “This is the first study that unequivocally shows a link between chronic light-dark inversions and breast cancer development.”
The study, published this week in the journal Current Biology, found that mice that didn’t sleep at regular intervals were much more likely to develop cancer. During the study, the body clocks of some of the mice were delayed by 12 hours every week for a year. In the mice with irregular sleep patterns, tumors developed in as few as eight weeks. The study also found that the mice who slept at irregular intervals were 20 percent heavier, despite being fed the same amount of food.
The most often cited reason for irregular sleep patterns is working changing shifts for an employer. The report shows that shift workers who don’t always have the same sleeping schedule may be at a higher risk of developing cancer in the future. Previous studies have shown that flight attendants and shift workers have a much higher risk of diseases like breast cancer. The theory is that shift work interrupts the body’s internal clock, increasing the body’s susceptibility to disease.
Based on the results of the study, the researchers say that women with a family risk of breast cancer should avoid taking jobs that require working shifts that run late into the night. However, other factors may also be contributing to the higher rates of cancer in shift workers, including social class, activity levels, and dietary habits. The researchers behind the study acknowledged that further human trials were necessary to definitively establish the association as a fact.