Sleeping Over 8 Hours Is Really Bad for You, According to Scientists

Updated 04/26/19

You’ve been surviving on minimum sleep for a month, desperate to weave in a few extra hours so why is it when you do manage to hit the snooze button that you end up feeling more groggy than before? While some profess that it’s your body's way of realizing what it’s been missing, it’s recently been flagged up that too much sleep could potentially have unhealthy side effects and that oversleeping could be a red flag for underlying mental or physical issues. Keep scrolling to find out what might be going on when you spend a little longer under the sheets.

Too much sleep
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What Kind of Issues?

A recent study by Keele University, that involved scientists looking at the data from 74 sleep studies, found that sleeping for a 10 hour period is linked to a 30% increased risk of early death, compared to sleeping for just seven hours. Another study reported that people who slept for more than eight hours a night had a 46% increased risk of stroke compared to those who slept for between six and eight. However, it has to be noted that this was just an ‘association’ so don’t take it as gospel.

More likely to have an obvious impact is the link between oversleeping and depression. The thinking behind this is that the more sleep you get the less you’re out and about being active so there’s less chance of your body and brain releasing those happy endorphins. Plus all that sedentary sleep increases your risk of back pain and sore muscles as the body simply isn’t flexing as much. Another study, albeit very small (14 people) also showed that excessive sleeping resulted in an overproduction of IL-6, a protein connected with inflammation. Which would explain that achy breaky feeling when you wake after those extra hours of shuteye.

Finally, there’s that fuzzy-headed fog. You might not be imagining it as the amount of sleep you have can directly impact your cognitive behavior functions such as focus, memory and decision making. Or it could be that you’ve slept past your usual morning coffee break so your blood sugar levels are a bit skew-whiff.

So How Long Is Too Long?

Although on average it’s thought that the optimum number of hours is actually seven, not eight, there isn’t a clear-cut answer according to sleep expert, Dr. Roger Henderson. “Each individual’s sleep needs vary depending on age, lifestyle, and health. However, sleep is a clear indicator of our overall wellbeing so to assess how much sleep you need you should investigate what’s affecting the quality and quantity of your sleep.”

That’s because quantity doesn’t mean quality – you could be in bed for eight hours but waking up during the night or struggling to dose off in the first place. Henderson drums home that this is why it’s so important to listen to your body. “If you’ve had a particularly busy week and are feeling run down, you need time for your body to heal itself.” In which case, don’t panic if you’re sleeping through your alarm. It’s only if it turns into an ongoing habit of eight hours plus you might want to reassess the situation.

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