It's not a good plan to skimp on sleep. A regular seven to nine hours a night puts you in a better position to live longer, and better..
There’s plenty of folk living out there who want to have fun now, and sleep when they’re dead. But nope, not a good plan. You're better off getting your regular seven-nine hours of sleep each night – so you can live longer and better.
So let’s update our Sleep Knowledge DataBank. How about starting with how much sleep we really need. It varies a little. But once you start sleeping less than six hours at night you’re much more likely to get various cancers, Alzheimer’s Disease, diabetes and fat.
There are several different ways that too little sleep makes you heavier.
Looking at hormones, not enough sleep will simultaneously increase blood levels of a hormone that makes you feel hungry while at the same time suppressing another hormone that makes you feel full. Then looking the brain, the regions related to impulse control are turned down, or even off. To make things worse, at the same time, the activity of your amygdala (another part of your brain) is pumped up (the amygdala drives fun-seeking behaviour, and that includes eating fatty foods). Putting it all together, people who are sleep deprived will choose foods that increase their energy intake by up to about 50%.
But what if you are deliberately eating less to lose weight, while at the same time being sleep deprived? Very annoyingly, your metabolism will hang onto its stores of fat, and for energy, break down your muscles instead. In fact, some 60% of this weight loss (while sleep-deprived) comes from losing muscle mass.
Sleep deprivation impacts kids as well. Now your average three-year-old child gets around 12 hours of sleep each night. But what about the three-year-old sleeping ten-and-a-half hours or less each night? Compared to the kid sleeping 12 hours each night, the short sleepers have a 45% increased risk of being obese by the time they get to the age of seven.
Now a global sleep study is accidentally carried out on over 1.5 billion people across 70 continents every year. We call it Daylight Saving. In the spring, as we roll into Daylight Saving, the day has only 23 hours so we lose a whole hour of sleep. The very next day there is a 24% increase in heart attacks around the globe.
Having inadequate sleep also affects male sex hormones. One study looked at healthy young men sleeping just four hours a night, for four nights. They ended up with testosterone levels of a male some 10 years older. In other words, in terms of hormonal virility, a few consecutive nights of inadequate sleep will age a male by about a decade. Similar changes in both female reproductive health and hormone profiles happen to young women who don’t sleep enough.
What about not enough sleep affecting a vaccine shot? Well, if you don’t get enough sleep in the week leading up to your annual flu jab, your immune system will produce less than 50% of its regular antibody response – and your vaccine will be far less effective. In another pathway related to the immune system, if you consistently get less than seven hours of sleep each night, you are three times more likely to get infected by the common cold from a rhinovirus.
Besides interfering with your body weight and your immune system, inadequate sleep is turning out to be one of the most significant lifestyle factors related to getting Alzheimer's disease. For some time, we have known that people who sleep six hours or less each night, or people who have sleep apnoea or insomnia – well, they have a higher risk of getting Alzheimer's disease.
First, a bit of background. As part of Alzheimer's disease, a sticky toxic protein called beta-amyloid builds up inside the brain. Luckily, deep sleep activates a massive flushing out of dangerous metabolic chemicals through what is called the “glymphatic system”. Either missing out on the full 7-9 hours of sleep, or even a lack of deep sleep in the first few hours of the night, leads to a sudden jump in beta-amyloid – in blood, in cerebrospinal fluid, and in the brain.
Now here is where evolution has been very unkind to us. This beta-amyloid chemical accumulates in those very brain regions that generate deep sleep! You can see that this is a very nasty positive feedback loop – less deep sleep leads to more amyloid which leads to even less deep sleep, which leads to even more amyloid and it just keeps repeating.
Interestingly, both Margaret Thatcher and Ronald Reagan* both reckoned that sleep time was wasted time, and they both came down with Alzheimer's disease.
But the good news is that treating sleep disorders in middle-aged and older adults can delay the onset of Alzheimer’s disease by 10 years.
So, if there’s one golden rule in life it is to get enough sleep.
*UK Prime Minister US President 1980s -90s
1. How much sleep should a person get each night?
2. What are two diseases that can occur because of too little sleep?
3. What is the function of the amygdala?
4. How can sleep deprivation impact kids?
5. How are men impacted by a lack of sleep?
6. How can a lack of sleep affect your flu shot?
7. What happened to Margaret Thatcher and Ronald Regan?
8. What is the golden rule?
Vocabulary – explain the following words and phrases
To skimp on
Folk
Simultaneously
Suppressing
Impulse control
Deprived
Inadequate
Annual
Sleep apnoea
Cerebrospinal fluid
Accumulates
Feedback loop