“There’s no evidence that you can oversleep,” said the Medical School’s Elizabeth Klerman. “Unlike chocolate cake you can eat when you’re not hungry, there’s no evidence you can sleep when you’re not tired.”
Experts from Harvard, Columbia University, the University of Miami, and the University of Massachusetts detailed the health implications of sleep in a conversation with CNN health reporter Jacqueline Howard on Thursday at the Harvard T.H. Chan School of Public Health.

“Sleep in many ways is associated with mortality — cardiovascular disease, diabetes, mental health, brain health, immune function, respiratory conditions, and cognitive function and performance,” said Azizi Seixas, an associate professor at the University of Miami Miller School of Medicine.
He and other panelists explored the health risks of long-term sleep deprivation and the fundamental role sleep plays in memory. According to Rebecca Spencer, a professor of psychology and brain science at UMass, “When you sleep, you’re taking this movie of your day and you’re putting it on replay, and it’s this great mnemonic device. It’s a way to really solidify the memories that we formed during our day.”
Those memories might include noise and other disruptions, introducing a wider challenge: While getting enough rest is important for everyone, the world can get in the way. Panelists zeroed in on noise pollution, racial disparities in sleep, and how policy decisions can leave us tired and vulnerable.
“We know, for example, that marginalized communities and racial and ethnic minorities are more likely to live in neighborhoods with socioeconomic disadvantage,” said Carmela Alcántara, an associate professor at Columbia University’s School of Social Work. “That can include neighborhoods that might have higher policing, neighborhoods that then have greater exposure to noise pollution, greater exposure to light pollution, and all these factors which we know impact short-term sleep and then can have these cascading long-term effects on sleep.”