A study published in the June 2003 issue of the Journal of the National Cancer Institute shows that women who regularly go to work at night
A study published in the June 2003 issue of the Journal of the National Cancer Institute shows that women who regularly go to work at night have an increased risk of colorectal cancer.
Dr. Eva S., of the Harvard University School of medicine, and colleagues note that earlier studies have shown that the risk of breast cancer is higher in women who go to work late at night, which is consistent with the findings of the study. Since night shift is a common phenomenon in developed countries, future studies should also assess the relationship between exposure to light and other cancers, as well as the risks associated with men.
The U.S. Bureau of Labor Statistics estimates that about 4% of adults have a night shift experience, the night shift will disrupt the normal secretion of melatonin, increase the level of other hormones, such as estrogen. Malignant tumors in women are often associated with estrogen, but for colon cancer, it is possible that melatonin, rather than estrogen, may affect the risk of developing the disease. If the anti cancer activity of melatonin is the mechanism of this study, it will open up a new field for the study of light exposure and cancer.
A total of 78586 women who participated in the nurses' health study program were assigned to work for more than 15 years within a month, with a total of more than 3 night shifts. The results showed that the risk of colorectal cancer was 35% higher than that of the control group.
Dr. Schernhammer says the new findings need further confirmation.