Sleep Duration and Cardiovascular Disease Mortality Among the NIH-AARP Diet and Health Study Cohort

Researchers asked nearly 240,000 adults aged 50 to 71 how long they usually slept. They then followed them for about eight years and compared deaths from cardiovascular disease, meaning diseases of the heart and blood vessels. People who reported about 7 to 8 hours of sleep had the lowest death risk. Both very short sleep and very long sleep were linked with more cardiovascular deaths, especially 9 or more hours, but this study could not prove that sleep duration caused those deaths.

What this means for you: This supports aiming for a regular 7 to 8 hours if that suits you, but it does not show that forcing a specific number will prevent heart disease. Persistent short or long sleep may be worth discussing with a healthcare professional, since illness or poor sleep quality could be the real cause.