As December rolls around each year, sleep cycles shift into low gear, synching up with shorter daylight hours. As a result, you might find yourself sleeping more than usual and actually loving it, especially when you awaken feeling refreshed.
Unfortunately for more people than ever, this just isn’t the case. They continue to fight the urge to sleep more and continue to burn the candle at both ends of the wick, and pay the consequences with diminished energy and focus In the past, doctors didn’t really consider not getting a full night sleep a health problem (although sleep disorders have long been recognized as quality of life zappers). After all, many of them were short on sleep. But a number of new studies clearly demonstrate the importance of getting between seven to eight hours of sleep night for overall health, weight and wellbeing. In fact, when people get less than six hours of sleep a night, they risk gaining weight (even when they are active) and of developing a variety of chronic health conditions.
Most people understand the link between sleep and the ability to function. In fact, for many, the fatigue, bad mood, or lack of focus that follows a night of inadequate sleep is all too familiar.
Of course, everyone knows the rare soul who seems to thrive on four to five hours of sleep, but what you don’t see is the long-term consequences of that habit. Too little sleep—particularly on a regular basis—can lead to diabetes, high blood pressure, and heart disease, even when other predisposing factors aren’t present, and all of these are conditions that typically shorten life expectancy.
Not so surprising, the so-called power sleepers—people who habitually sleep less than six hours a night—are much more likely to have a higher than average body mass index (BMI), while people who sleep eight hours have lower BMIs. That’s one of the factors researchers noted when they started looking at the mechanisms involved in regulating metabolism and appetite, and begin to see the connection between sleep and obesity.
The primary culprits are the hormones you secrete during sleep that help control appetite, energy metabolism and glucose processing. Too little sleep upsets the balance of leptin in particular. This is the hormone that alerts the brain when appetite has been satisfied. Insufficient sleep also increases secretion of hormones like cortisol—the so-called “stress” hormone, and increases levels of ghrelin. This hormone, according to research published a few years ago in the International Journal of Obesity, not only stimulates the brain’s appetite center, but also favors the accumulation of lipids in visceral fatty tissue (abdominal fat), which is considered to be the most harmful. Some scientists think ghrelin may be at the root of food cravings that compel you to eat sweets when you’re low on energy. Perhaps even worse, too little sleep can leave you too tired to burn off the extra calories you consume.
It also increases the secretion of insulin, which regulates glucose processing and promotes fat storage following a meal, which ultimately puts you at risk for developing diabetes.
Studies show that people who usually sleep less than five hours a night have a greatly increased risk of having or developing diabetes. Researchers think this may be because less sleep means slower glucose processing.
Insufficient sleep may also be a risk factor for cardiovascular disease and stroke. Studies have found that when people with hypertension suffer a single night of poor sleep their blood pressure stays elevated throughout the following day. Even short periods of insufficient sleep can raise blood pressure—so, perhaps, it’s no surprise that you’re most likely to die right after you get up in the morning. Researchers have also found a link between sleeping too little (less than six hours) or too much (more than nine hours) and an increased the risk of coronary heart disease in women.
Chronic lack of sleep has also been linked to depression, anxiety and other emotional distress. In studies, all of these decreased dramatically when subjects returned to a normal sleep schedule.
So this winter, take heart in knowing that the extra zzzs you get might not only help you lose weight and feel emotional better, but also boost your immune function. With all the viruses and bacteria floating around in winter, you’ll do well to actual skip your work out and sleep instead. Studies show that people who slept more when they were feeling sick, got well faster than those who failed to take heed, and continued to cut their sleep short.
Researchers from the San Diego School of Medicine have studied women age 50 to 81 since 1995 to try and establish a link between sleep and mortality, and recently announced that it looks like women can do just fine on five and a half hours of sleep a night. But the caveat is that this means “occasionally” not nightly. All the long term studies show that those who drop down to five hours or fewer face a 70 per cent extra risk of dying from all causes.
All that said, a considerable amount of sleep-related behavior, like when and how long a person needs to sleep, may actually be regulated by genetics. But that doesn’t mean that you shouldn’t consider the risks and do what you can to improve the quality of your sleeping life.