Sleep, new research reveals, is a master regulator of health. A sleep deficit or disruption can create wide-ranging havoc, compromising our immune system, causing inflammation, and damaging our genes. Losing just an hour of sleep a night increases risk of cancer, heart attack, stroke and type 2 diabetes.
Lack of sleep can also lead to memory loss, negatively affect people’s reflexes and decision-making skills, cause hearing loss and psychiatric disease, and impede sexual function.
And it’s not just people who suffer from sleep disorders like insomnia and sleep apnea who have to worry, says James Maas, PhD, a recently retired Cornell scientist and one of the world’s foremost sleep researchers. He says at least seven out of 10 Americans aren’t getting enough sleep and they’re at risk for serious health problems, as well.
“People devalue sleep and are completely unaware of what happens to them when they have a deficit,” Maas says. “As a society we are so habituated to low levels of sleep that most of us don’t know what it feels like to be fully alert and awake.”
We treat sleep like a “tradable commodity,” adds University of Chicago sleep researcher David Gozal, MD, sacrificing it for work, entertainment or some other lifestyle choice. In large part, he believes, we do this because it can take months or even years for a disease caused by sleep deficit to fully emerge.
“Sleep is the food of the brain,” says Gozal. And a great many of us aren’t just hungry for sleep, he notes. “We are starving.”
Sleeplessness Can Increase Inflammation & Risk for Disease
The damage caused by sleep deficit first dawned on Gozal, a pediatrician, about 20 years ago, while treating children with sleep apnea, in which breathing is rendered irregular (through physical obstruction or damage in the brain) and sleep is interrupted. After they had surgery to correct the problem, many children appeared transformed. Those labeled mentally challenged became stellar students, and friendships and personalities improved dramatically.
Over the years, researchers traced apnea to cognitive and psychiatric impairments, high cholesterol and atherosclerosis, high blood pressure, obesity, and type 2 diabetes, to name a few.
Eventually, Gozal realized the apnea findings were applicable to adults who were burning the candle at both ends, whether they had apnea or not. He and his colleagues traced perturbations in sleep to a surge of pro-inflammatory molecules — from dangerous cytokines to C-reactive protein — that did massive damage throughout the body. For example, in adipose tissue (body fat), these pro-inflammatory molecules set the stage for obesity and type 2 diabetes; in the cardiovascular system, heart disease; in the brain, neuronal loss.
Fortunately, it’s often possible to reverse the damage caused by sleep loss. A 2007 study published in the journal Circulation, for instance, followed 26 children with apnea who had the inflammatory precursors of cardiovascular disease. By curing the apnea, Gozal reversed the damage in all except six of the children, and that’s because those six had a genetic predisposition to the disease.
This led to a seminal finding: The pro-inflammatory state caused by sleeplessness makes those who are already at genetic risk for certain maladies far more vulnerable to triggering them into an active disease state.
Gozal explains, for example: “If you are born with a familial predisposition to Alzheimer’s at age 70, a sleep disturbance could bring it on at an earlier age, say 55.”