Key points from article :
Synchronizing sleep to match our internal body clock, explain association with reduced risk of heart attacks.
The body's natural 24-hour rhythm is important for wellbeing and alertness.
Researchers collected data on sleep and wake times over seven days.
Followed up in terms of heart and circulatory health over an average of six years.
Just over 3,000 of the adults developed cardiovascular disease.
Occurred in people who went to bed later or earlier than the "ideal" 10pm to 11pm.
David Plans, from the University of Exeter, says "...early or late bedtimes may be more likely to disrupt the body clock, with adverse consequences for cardiovascular health.
Sleep between 10 and 11pm could be the sweet spot for most people to keep their heart healthy long-term.
Study can only show an association and can't prove cause and effect.
More research is needed into sleep timing and duration as a risk factor for heart and circulatory diseases.
Research by University of Exeter published in European Heart Journal.
