Night Shift

It’s 6:00 in the evening.

As I prepare dinner, my next door neighbor, a single parent, gets ready for work.

I’ve always wondered how her kids are taking her schedule. They rarely see each other, not even on weekends. The children will still be in school when she leaves for work. They’ll be asleep by the time she comes home.

I’ve read somewhere that relationships suffer tremendously because of family members’ divergent schedules. Moreover, the health of night workers also gets a lot of beating.

Women who work regular night shifts have a high risk of colon cancer and breast cancer, according to data extracted from a study of nurses.

The link may involve melatonin, a hormone produced by the brain's pineal gland. Production of melatonin peaks at night during sleep.

One theory is that shift work disrupts normal melatonin production and increases levels of other hormones such as oestrogen. Women's cancers are often linked with oestrogen and melatonin.


Melatonin is produced at night, and regular exposure to sunlight affects the production cycle, which peaks in the middle of the night. Artificial light suppresses melatonin production.

Melatonin is known to have anti-carcinogenic properties, and a link between exposure at night and cancer risk through the melatonin pathway could offer one plausible explanation for the increased risk that has been observed, according to a study.



Indirect support of the melatonin/breast cancer connection comes from an earlier study of blind women, who were found to have a 20 percent to 50 percent reduced risk of breast cancer as compared to a comparison group of women diagnosed with stroke and cardiovascular disease. The theory behind this reduced risk: Because blind women are immune to fluctuations in light, their melatonin levels remain constant, which also keeps their circulating estrogen levels in check.


Other than the melatonin factor, sleep also allows our body and mind to reenergize, rejuvenate and restore. Sleeping also enables the body to repair and renew tissue. It allows the brain to organize long term memory and integrate new information.


So what's the experts’ verdict of these findings regarding graveyard-shift work and breast cancer?

From a research point of view, it may be wise to focus on the general notion that anything that disrupts the normal biology of the body might affect hormones that influence cancer risk.



I hear her car move out of the garage. It’ll be a long night for this shift worker and a much longer wait for her kids.