A large, new study in the European Heart Journal (116,632 people across 21 countries) found that getting at least 6–8 hours of sleep a night is optimal, but getting more might not be. People who slept 8–9 hours had a 5 percent increased risk for cardiovascular disease or death; those who slept 9–10 hours had a 17 percent increased risk; and those sleeping more than 10 hours boosted their risk by 41 percent. A possible reason: People have underlying conditions causing them to sleep longer.
