Any new mother, shift worker or insomniac, will tell you that lack of sleep is a killer. That’s nothing new – but it may surprise you to learn that there is a grain of truth in their words, with recent research showing that a good night’s rest can add years to your life.

A research team at Beth Israel Deaconess Medical Center in Boston uncovered these findings. According to them, men could live as much as five years longer and women two years longer if they get good quality sleep. ‘Quality’ is the keyword here. It’s not just about the number of hours you spend in dreamland (although seven to eight hours is ideal).

Quality sleep is also defined by other factors:

• Whether you battle to fall and stay asleep,
• If you need to use sleep medication, and
• Whether you wake up feeling rested.

An even more disturbing finding of the study: 8% of deaths from any cause have poor sleep at their root.

The link between sleep and longevity
Clinical neuropsychologist Michelle Baker chairs the Allied Group for the South African Society for Sleep Health. She is also the Vice Chairperson of the South African Society of Sleep Health. Michelle hesitates to put a number to the years of extra life a good night’s rest may give you but says there is a clear link between sleep and longevity. This is because so many things happen while you sleep. She explains that, far from being in a “death-like” state, the body undergoes a gamut of processes. These include the release of human growth hormone, which maintains muscle and bone, and the renewal of organs like the skin.

Our brains use this time to process information, and this is a key part of the health implications of sleep. “During REM sleep, the brain’s glymphatic system clears out unneeded cells and debris,” Michelle continues. Think of it as a rubbish removal system. Failure to eliminate these ‘extras’ has consequences, as anyone who hasn’t removed their weekend refuse knows. “Lack of sleep won’t necessarily lead to dementia, but sleep certainly refreshes the body and helps it function at its best.”

The area of the brain that controls sleep, the hypothalamus, is linked by pathways to several nerve centres. These nerve centres are involved in multiple systems responsible for everything from suppressing appetite to how we experience pleasure and pain. If these systems are in sync, you feel great. But when a lack of sleep impacts how they operate, your body will let you know in no uncertain terms.

Know your biological rhythm
Thinking your well-being hinges on your night’s sleep can make you feel pressured. What if you’re not getting those eight hours? Michelle says it’s important to note there are “short sleepers” who can get away with five and a half to six hours of sleep. And then there are “long sleepers” who feel refreshed only if they’ve clocked up a good 10 hours. “While the average person needs around 7,5 hours, it’s important to know your biological rhythm to know how much you need to be at your best.”

Michelle points out that sleep is part of a 24-hour cycle, which includes being awake. “If you’ve had a stressful day that’s left you feeling completely wired, you’re unlikely to sleep well. You’ll feel tired the next day, and the unhealthy cycle continues.”

It’s also important to understand that age affects how much sleep we need. For example, a woman going through menopause may feel alarmed that she is no longer getting her usual number of hours. In reality though, this is because her sleep naturally shortens as her body changes.

The bottom line?
If you feel alert and refreshed when you wake up, your sleep is most likely doing its job.