How much sleep are you getting? Judging by how you’re feeling, you’d probably say ‘not enough’.
Many of us dealing with the drudgery of the day often don’t feel very well rested and are likely to wish for more snoozing time. But actually, we might be sleeping too much already, depending on our age.
The ideal amount isn’t actually eight hours for those over 38 years old, according to scientists who conducted a major new study.
The University of Cambridge and Shanghai’s Fudan University examined the sleeping habits of nearly 500,000 adults aged between 38 and 73 and found that the ideal amount of sleep may be seven hours.
Participants were tested on their cognitive abilities and asked about their sleeping patterns, wellbeing, and mental health.
Researchers also sourced brain-imaging and genetic data for up to 40,000 participants in the study to get a better insight into their wellbeing.
Interestingly, they found that getting too much sleep and not enough has the same consequences. While traditionally, we’re told to get eight hours, scientists found that this amount, or any more (or less than seven) have a negative effect on our bodies as we age.
They found that too much sleep and not enough both had a detrimental effect, causing mental health issues and ‘worse cognitive performance’.
The study also showed that being consistent is key, so getting six hours one day and then nine the next can still leave you feeling groggy and tired.
So, why exactly do we feel a brain fog when we wake up some mornings?
Researchers say that it could be due to slow-wave deep sleep being disrupted during shorter bouts of slumber. This means the brain doesn’t have enough time to clear out the toxins.
Not only is getting the right amount of sleep better for your overall wellbeing, it’s good for our memories. That’s because scientists found that the hippocampus - the memory centre - is also affected by a lack of or excess of sleep.
So the older you get, the more you might want to get into the routine of achieving seven hours a day. This also has the added benefit of decreasing the likelihood of illness.
Prof Barbara Sahakian from the University of Cambridge, one of the study’s authors, said: “Getting a good night’s sleep is important at all stages of life, but particularly as we age. Finding ways to sleep for older people could be crucial to helping them maintain good mental health and wellbeing and avoiding cognitive decline, particularly for patients with psychiatric disorders and dementia.”
The Sleep Foundation also has similar advice for the ideal slumber time, based on age group.
It suggests that older adults should aim for seven-eight. While the Cambridge study says to go for the lower number in that range, as long as you feel well-rested with the amount you currently get, then it’s all good.