Another study says that working at night significantly increases the risk for breast cancer.
University of Georgia researchers say that artificial light disrupts the body’s circadian rhythm and greatly increases the risk for breast cancer.
The obvious recourse is to go to bed early and get up early. But this is not possible for someone who can’t change work shifts.
However, some women who work out of their home have gotten into the habit of going to bed at 4 a.m. and getting up for the day at 11 a.m.
Unemployed women, as well, may find that they’ve developed a habit of staying up way past midnight and awakening around noon.
The University of Georgia study took a look at flight attendants because they usually work night and day shifts.
It was found that working as a flight attendant was associated with a higher risk of breast cancer.
But what about other variables that could account for this increased risk, such as the extremly high altitude (even though the interior of planes is pressurized)?
This was not investigated. Neither were other variables that could possibly be associated with a flight attendant’s lifestyle.
This is why it’s important to note that the risk was only associated with night work. Cause-and-effect was not established.
Nevertheless, the hormone melatonin needs some mentioning.
This hormone is dispensed by the body overnight during sleep — but optimal amounts are released if sleep occurs just after dark and then rising for the day occurs at sunrise — which is not a practical schedule for many women.
The theory is that when the sleep-wake cycle is disrupted by artificial light, the secretion of melatonin is reduced.
How seriously should you take these studies?
“The epidemiological evidence regarding this is inconclusive — with some studies showing no effect and others showing a slight increase in breast cancer risk,” says Dr. Aashini Master, DO, a medical oncologist with a special focus on breast cancer treatment.
What if a woman who’s been working a third shift for several years returns to a daytime shift?
Would this undo any harmful effects of night work on breast cancer risk?
“As such, I do not believe we have enough information to know whether the effects are reversible,” says Dr. Master.
“But theoretically, the hormonal changes induced by nightshift work would return to baseline once a woman was to no longer work the nightshift.”
KAB for Breast Health
Dr. Master is with the Keep A Breast (KAB) Foundation, which launched its Keep a Breast app Sept. 1, 2020.
The Keep a Breast app focuses on information, support and access, and connects users who’ve discovered something worrisome with a telehealth medical professional through KAB’s partnership with Carbon Health, a technology-enabled healthcare provider – allowing users to have direct, instant support.
r. Master
