By Janis Siegel, Jewish Sound Correspondent
It’s happened to all of us.
Whether we drank too much coffee before bedtime, ate too much rich or spicy food, exercised too close to lights out, or consumed too much alcohol, we toss and turn, and maybe fall asleep for a while before waking up again and again throughout the night. We try to drift back into a sound sleep so we can be ready for a jam-packed day, but to no avail.
Sleep scientists call it “sleep fragmentation.”
SF is common in people who suffer from obstructive sleep apnea and research has shown they have a greater risk of developing cancer and they often die earlier.
OSA sufferers are awakened multiple times throughout the night as they sleep, trying to regain air flow in their throat that becomes repeatedly blocked by soft tissue.
This type of disturbed sleep pattern seems unavoidable for all of us at times, but according to a study designed and led by Dr. Fahed Hakim, a pediatric pulmonary and sleep expert at Rambam Medical Health Care Campus in Israel, it can impact anyone’s overall health.
“We should consider sleep as an important part of our life and we (should) take care of it as good as we take care of our daytime life,” Hakim told The Jewish Sound. “Absolutely any disturbance, even in healthy people, could lead to sleep fragmentation and may affect cancer progression. It does not have to be just Obstructive Sleep Apnea.”
In his study funded by The National Institutes of Health and published in the Jan. 2014 issue of Cancer Research, Hakim and his group from the University of Chicago and the University of Louisville found that mice whose sleep had been interrupted over a seven-day period and then injected with cancer cells developed tumors that were twice as large and were more aggressive than the group that was not sleep deprived and were also injected with the cancer cells.
Half of the mice were awakened by a nearly silent motorized sweeping brush-type device in specifically timed two-minute intervals during daylight hours, when they typically sleep. The other half of the mice were not touched.
Researchers evaluated all of the tumors after 28 days. Although all of the mice developed cancerous tumors after 12 days, the sleep-deprived mice not only had larger tumors but the tumors were more aggressive and had spread into surrounding tissue and bone.
When researchers performed a second similar study injecting the cancer cells into the thigh muscles of the mice, an area on the body that is more resistant to malignancies, the tumors became even more aggressive.
The result of the research adds to the decade-long trail of evidence associating sleep and disease progression but it is the first time poor-quality sleep has been linked to cancer.
Hakim also believes that the deprivation of oxygen in OSA sufferers as they sleep also contributes to proliferation of the disease.
“We believe that the sleep disruption or fragmentation is the leading cause for the cancer progression,” said Hakim, “but it does not mean that hypoxia [a lack of oxygen] has no mechanistic involvement. We have another publication looking at the effect of hypoxia that has different effects.”
A 2012 Israeli report from its Central Bureau of Statistics named cancer as the number one cause of death there, claiming the lives of one out of every four Israelis between 2000 and 2010, replacing heart disease as the main cause of death in Israel from the 1970s until 2000.
The third most prevalent death-causing disease in Israel is diabetes, the report said.
Hakim’s study provides yet another reason to look closely at our daily habits and to structure our days in sensible and healthy ways.
“It’s the immune system,” said David Gozal, the study director and chairman of pediatrics at the University of Chicago Comer Children’s Hospital in a UChicago News interview. “Fragmented sleep changes how the immune system deals with cancer in ways that make the disease more aggressive.”
“Fortunately, our study also points to a potential drug target,” he said. “Toll-like receptor 4, a biological messenger, helps control activation of the innate immune system. It appears to be a lynchpin for the cancer-promoting effects of sleep loss. The effects of fragmented sleep that we focused on were not seen in mice that lacked this protein.”
The Centers for Disease Control and Prevention reports that over 78 million people in the U.S. have said they occasionally don’t get enough sleep, and that nearly 31 million have chronic insomnia.
“We are looking at the effect on metastatic progression and aggressive [cancers],” Hakim said, “and considering different aspects of treatment.”
Longtime JTNews correspondent and freelance journalist Janis Siegel has covered international health research for SELF magazine and campaigns for Fred Hutchinson Cancer Research Center.