Going to bed during the ‘golden hour’ between 10pm and 11pm slashes the risk of developing heart disease, according to a major study.
Researchers discovered a correlation between sleeping late and higher risk for strokes, and especially among women.
According to University of Exeter, going to sleep after midnight can damage your heart because you are less likely see the morning sun. This disrupts the body’s natural clock.
The study examined data from over 88,000 British citizens aged 43 to 74.
The wrist watches were worn by participants for one week. They monitored when they fell asleep, woke up and answered any questions regarding their daily lives.
These records were compared to their five-year medical records, which included cases of heart attack, stroke, and heart disease.
According to research, those who go to bed between 10 and 10.59 each night have the lowest risk of developing heart problems.
Researchers at the University of Exeter looked at data from more than 88,000 British adults between the age of 43 and 74. The wrist watches were worn by participants for one week. They monitored when they fell asleep, woke up, as well as answering questions about how their life was going. Researchers found that people who went to bed between 10.59 and 10:59 each night had the lowest risk of developing heart disease.
Heart problems are more likely to develop in those who go to bed at night.
The risk of falling asleep before 10PM was 24% higher than those who fell asleep between midnight and 11pm. Rates were 11% higher for those who slept from 12 to midnight.
The research, published in the European Heart Journal, concluded that encouraging people to maintain a regular bedtime could help prevent cases of heart disease at ‘minimal cost’.
Lead author Dr David Plans said: ‘The body has a 24-hour internal clock, called circadian rhythm, that helps regulate physical and mental functioning.
‘The results suggest that early or late bedtimes may be more likely to disrupt the body clock, with adverse consequences for cardiovascular health.’
Dr Plans said: ‘Our study indicates that the optimum time to go to sleep is at a specific point in the body’s 24-hour cycle and deviations may be detrimental to health.
‘The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock.’
According to the study, the strongest link between heart disease risk and bedtime was found in women. This may have been due to hormone differences or the menopause.
While men who stay up until midnight were not at risk for developing ill health, those who go to bed after 10pm are more susceptible to having heart disease.
Dr Plans said: ‘It may be that there is a sex difference in how the endocrine system responds to a disruption in circadian rhythm.
‘Alternatively, the older age of study participants could be a confounding factor since women’s cardiovascular risk increases post-menopause – meaning there may be no difference in the strength of the association between women and men.’ Research shows that decreased oestrogen levels after the menopause increase women’s risk of heart disease.
According to the study, encouraging millions to go to sleep before 11pm can reduce heart disease risk.
Dr Plans said: ‘While the findings do not show causality, sleep timing has emerged as a potential cardiac risk factor – independent of other risk factors and sleep characteristics.
‘If our findings are confirmed in other studies, sleep timing and basic sleep hygiene could be a low-cost public health target for lowering risk of heart disease.
‘Sleep timing would be an attractive target for interventions to reduce CVD risk owing to its minimal cost and invasiveness.
‘This intervention could take the form of public health guidance, structured intervention programmes, or technology-based solutions such as smartphone apps.’
Around 160,000 British people die annually from cardiovascular disease.
Regina Giblin, Senior Cardiac Nurse at the British Heart Foundation, said: ‘This large study suggests that going to sleep between 10 and 11pm could be the sweet spot for most people to keep their heart healthy long-term.
‘However, it’s important to remember that this study can only show an association and can’t prove cause and effect. Further research on sleep timing and duration is required to understand the risk factors that can lead to heart disease and circulatory problems.
‘Getting enough sleep is important for our general wellbeing as well as our heart and circulatory health, and most adults should aim for seven to nine hours of sleep per night.
‘But sleep isn’t the only factor that can impact heart health. It’s also important to look at your lifestyle as knowing your numbers such as blood pressure and cholesterol levels, maintaining a healthy weight and exercising regularly, cutting down on salt and alcohol intake, and eating a balanced diet can also help to keep your heart healthy.’