We’re often warned about getting less than 7 to 8 hours of sleep a night. Short sleepers—variously defined as people who sleep 5 hours and less or less than 6—are more susceptible than normal sleepers to a host of problems: cardiovascular disease, obesity, diabetes, cancer, and dementia. Many people with insomnia fall within that 5- to 6-hour range. Rarely do we get encouraging news about our prospects for a healthy life.
But recent research on genetic mutations tells a different story. Not only does it begin to explain some of the differences in sleep duration among human beings. It also suggests that short sleep may not necessarily have adverse effects on our health and quality of life.