All of us have an internal body clock called the circadian rhythm, or circadian cycle. It’s a 24-hour clock that regulates when we feel sleepy, hungry, and alert. The circadian rhythm also has a role to play in our mood and mental health, metabolism, and regulation of blood sugar and cholesterol. This internal clock is driven by light — meaning when it’s light out, our body naturally becomes alert and when darkness comes, it prepares to head to bed.
With night shifts, there is a disruption in this natural order of the circadian rhythm. This can change the way certain chemicals work in your system. For example, melatonin, which we refer to as the sleep hormone, is secreted from the brain’s pineal gland in response to darkness. It promotes sleep. Turns out, it performs another important role of inhibiting the growth and spread of cancerous cells. When there’s a disruption in your circadian rhythm, melatonin levels in your system can be reduced. This could put you at more risk of developing cancer.
It is also possible that a disrupted sleep schedule can negatively impact your immune system. A weak immune system puts you at greater risk for illness. Night shifts also mean a lack of exposure to daylight and therefore vitamin D. Science has previously linked low vitamin D levels with cancer risk. Shift work aside, are there other sleep mistakes you’re making that are putting you at risk of cancer?