Cancer
Just hearing or even seing the word cancer is enough to strike fear in the hearts of most people and for good reason:
The Canadian Cancer Society, estimates that in Canada, based on the current incidence rates, 39% of women and 45% of men will develop some form of cancer during their lifetime. Plus, cancer is the leading cause of early death in Canada. An estimated 166,400 new cases of cancer and 73,800 deaths will occur in Canada in 2008 as a result of cancer.
As a shift worker, unfortunately you are at an even greater risk of developing cancer. The International Agency for Research on Cancer (IARC), which is a part of the World Health Organization (WHO) has concluded that shiftwork that involves circadian disruption is probably carcinogenic, meaning that it probably causes cancer. The most destructive type of shiftwork is night work otherwise known as the graveyard shift.
Medical research studies have shown that long-term female night workers have a significantly higher risk of breast cancer than their counterparts that work daytime hours.
Excess prostate cancer has been reported in firefighters, health practioners, physicians and law enforcement personnel, all of which typically work some degree of night shift work.
The main mechanism proposed as the cause for this phenomena is light at night. Studies show that even constant dim light at night can increase tumour development. Any mechanism that increases light exposure during the night, decreases the amount of time available for melatonin production and this increases the risk of all cancers. Aside from breast and prostate cancer, this effect has also been shown in intestinal and liver cancers.
Disruption of the normal circadian rhythm results in less secretion of the hormone melatonin. Melatonin is believed to have cancer protective actions because it reduces levels of the reproductive hormone levels associated with tumour activity, it is on its own a very strong antioxidant and it also increases expression of the tumour suppression gene p53. Therefore, reducing melatonin levels at night increases the incidence and growth of tumours.
Stand Six Inc. is dedicated to understanding the relationship that exists between cancer and shift work. Our Shift Solution Model will help you to achieve greater health and our section on Protecting From Cancer will show you specific ways that you can protect yourself from this insidious disease.