While the link between sleep and a healthy heart is well established, researchers are still devoted to the details. A new study suggests there might even be the best possible time, within our 24-hour body clock, for falling asleep.
Of course, the reasons for not obtaining the right sleep, whether it’s the best amount or right timing are not always within our control. So anyone struggling with their sleep should seek medical advice and focus on whatever they need to do that works for them—as telling a specific bedtime may have the opposite impact on some. But for the rest of us it may be helpful to know that falling asleep between 10-11 pm seems to hit the sweet spot for a healthy cardiovascular(心血管的) system.
“The body has a 24-hour internal clock, called circadian rhythm, which helps regulate physical and mental functioning.” says University of Exeter psychologist David Plans. “While we cannot conclude causation from our study, the results suggest that early or late bedtimes may be more likely to interrupt the body clock, with harmful consequences for cardiovascular health.”
Analyzing wrist-worn accelerometer data from 88,026 participants in the UK Biobank study, the research team was able to compare sleep timing over a seven-day period with later health outcomes. The dataset included 3, 172 cases of cardiovascular disease, during almost six years of tracking participants.
The team found falling asleep after midnight or before 10 pm was associated with around a 25 percent increase in risk of cardiovascular disease, compared to falling asleep between 10-11 pm. This increase in risk dropped to 12 percent for those who fell asleep between 11-12 pm. “The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock.” says Plans.
This sort of study can’t determine if sleep timing itself contributes to heart disease—it may be other behaviors linked to staying up late, like staying out drinking or stress keeping people awake that are causing the problems.
8. What is the author’s attitude to the so-called specific bedtime?
A.Doubtful. | B.Ambiguous. | C.Objective. | D.Uncaring. |
9. What can we learn according to what David says?
A.Circadian rhythm is named a 24-hour internal clock. |
B.Early or late bedtimes interrupt cardiovascular health. |
C.The body helps control physical and mental functioning. |
D.The body clock is less interrupted by early or late bedtimes. |
10. What did the team find according to paragraph 5?
A.Sleeping after midnight may cause the worst. |
B.Staying up late is likely to reduce the risk of heart disease. |
C.Falling asleep between 11-12 pm does more harm to one’s body. |
D.Changes of the body clock aren't related to sleeping before 10 pm. |
11. What can be concluded from the text?
A.Enough sleep is largely important. |
B.Sleep contributes to a healthy heart. |
C.Cardiovascular disease leads to heart disease. |
D.The best time to fall asleep should be identified. |