We all know getting enough sleep is essential, and that lack of restful sleep is a very real health concern. But a large-scale study has found too of a good thing can also pose a threat, particularly in middle-aged and older people.
The British study, published in Neurology magazine, involved 10,000 people and was aligned with meta-analysis of 11 other studies. In other words, this was an extensive study and the findings are quite specific.
Researchers asked almost 10,000 people aged between 42 and 81 the average number of hours they slept daily and whether they generally slept well. Participants were monitored for nine-and-a-half years to see whether or not they had a stroke.
What they found was that long sleeps (more than eight hours) were associated with a significant (45 per cent) increase in the risk of stroke. Meanwhile, short sleeps of six hours per night showed an increased risk of stroke of 19 per cent.
It also seemed the quality of sleep had no impact on the results – basically, it was the actual number of hours spent in the sack, not how well or deeply you dozed that determined your stroke risk.
The researchers agree this issue needs to be examined more fully to determine the factors at play, such as whether certain illnesses, including sleep apnoea create patterns of longer but less restful sleep, although the consistency of the results seems to rule out the impact of a range of conditions.
The upshot is that too much – and too little – sleep increase stroke risk, and this should be addressed accordingly.
In February, the US-based National Sleep Foundation revised guidelines on how much sleep people need based on input from 18 sleep experts and over 300 studies. For those aged between 18 and 65 years, it recommended between seven and nine hours over a 24-hour period.
For those aged over 65, the suggestion is a narrower band of between seven and eight hours. In the light of the new findings, this narrower band may be the best idea for all adults, not just those aged over 65 years.
How many hours sleep do you get? Do you feel it’s enough, too much, too little?