Are you lacking sleep? Do you use indoor lighting and devices that produce light at night? If so, you may potentially be at a higher risk of getting cancer, according to researchers who suggest making changes in your sleep patterns and exposure to light.
Between stress, work, and school, more than 70 percent of Americans are not meeting the average recommended 8 hours of sleep they need, and it’s safe to say, America is suffering from a serious sleep crisis.
Both melatonin and cortisol hormones that are produced at night are believed to play an important role in fighting off cancer according to some doctors, sleep psychologists, and researchers.
Dr. Richard G. Stevens, Cancer Epidemiologist and professor at the University of Connecticut Health Center has been researching for many years and has tried to figure out why people get cancer, after proposing that cancer may be caused by an overload in iron, Dr. Stevens decided to do research in breast cancer.
Stevens wanted to know why breast cancer risk rises so dramatically as societies industrialize.
In 1987 he was featured in American Journal of Epidemiology proposing a radical new theory that “the use of electric lighting, resulting in lighted nights, may produce circadian disruption,” which causes changes in the hormones, one hormone in particular is melatonin, known as the hormone of darkness because it is secreted in the dark.
Melatonin works as a powerful antioxidant, which is thought to fight off cancer cells. Melatonin may also reduce the production of estrogen in the body, so with light interrupting the release of melatonin, estrogen levels rise, and too much estrogen heightens the growth of breast cancer.
“Melatonin needs darkness, if its dark melatonin rises … more light at night, less sleep, and less melatonin increases the risk of breast cancer,” said Stevens.
Stevens proposed a study on lab rats regarding the LAN (Light at Night) Theory, which states that the increasing use of electricity to light the night can raise your risk factors of getting cancer. Two groups of laboratory rats were injected breast-cancer-causing agents. One of the two groups was injected with Melatonin – sometimes called the hormone of darkness. Studies showed that the melatonin in the rats prevented them from getting breast cancer; the other group of rats that did not receive melatonin was not prevented from getting breast cancer.
However, Stevens does not advise anyone to take melatonin tablets. He suggests staying in the dark at night to naturally produce higher melatonin.
“Blind women have 50 percent less breast cancer than sighted women,” he said.
Blind women live in darkness 24 hours a day and sleep more hours than the average sighted American, thereby producing higher levels of melatonin and cortisol.
Today’s increasing use of electricity for night time lighting; television, computers, cell phones, and other devices have not only changed our lifestyles and sleep habits but can potentially change our hormonal rhythms.
“The sun suppresses melatonin, when the sun goes down we still have light…a thousand years back we would have twelve hours of darkness, keeping our melatonin levels high and our risk of getting cancer low,” said Stevens.
“Breast cancer is increasing globally for unknown reasons…and statistics show that women living in poor nations where there is less electric lighting, are less likely to get breast cancer,” said Stevens. Stevens added that America and Europe are at high risk of breast cancer.
Dr. David Spiegel, a psychiatrist and professor of Stanford University supports the LAN theory as well. He stressed that women who work night shifts have a higher chance in getting breast cancer.
“There is evidence that women who do night time shift work are in increased risk of getting breast cancer, and the World Health Organization has classified shift work as a probable cause and risk factor for cancer,” said Dr. Spiegel.
“Melatonin is an antioxidant. There is some thought that disruptive melatonin levels which happens when you don’t sleep well, may reduce the ability of the body to scavenge free radicals that can cause cancer,” said Dr. Spiegel.
Cortisol on the other hand is a circadian hormone produced by the adrenal gland that is released in response to stress. Cortisol helps to regulate the immune system and releases cells that fight off cancer cells. Cortisol levels rise after hours of sleep.
“We have evidence that if you have breast cancer loss of your normal daily rhythm of cortisol predicts earlier mortality,” said Spiegel.
Cortisol increases in the late hours of sleep. It’s at its highest when waking up, goes down throughout the day and is low by the evening.
“What we find is that if cancer patients lose their duration of cortisol their likely to die sooner,” said Spiegel. “People who wake up repeatedly during the night tend to have more abnormal cortisol levels than others.”
Cortisol, like melatonin, lowers the production of estrogen. High levels of estrogen may increase the risk of breast cancer. Spiegel believes that lack of sleep can cause cancer, altering the balance of these two hormones that influence cancer cells. Spiegel advises cancer patients to do what their grandmothers told them to.
“Eat well, sleep well, and get plenty of exercise.”
Stevens believes the LAN theory may be important for other forms of cancer and illnesses.
“It might be important for prostate cancer also,” he said.
“Lack of sleep and or light at night can be the reason for obesity and other illnesses,” he added.
So how do we lower our risk for getting cancer? Stevens and Spiegel are both clear. Sleep.
Stevens suggests staying in the dark at night and for those who wake up before dawn, he suggests the use of a dim red night-light.
Since a lack of sleep may be the leading cause of many illnesses and could increase the risk of getting cancer, turning the lights and TV off, putting the cellular phone down, closing your eyes and getting some sleep is just what the doctors ordered.