New research from Columbia University Irving Medical Center has found that sleeping too little or too much is linked to faster biological aging. The study looked at how many hours people slept and their biological age, using information from about half a million people in the UK Biobank. The healthiest sleep range was between 6.4 and 7.8 hours per night.

Researchers found that people who slept less than six hours or more than eight hours showed signs of faster aging in the body. Biological age measures how old the organs or body systems are, which is different from the number of years a person has lived.

The main result was clear: those who slept close to seven hours a night had the healthiest aging signs. The study suggests that keeping regular, moderate sleep may help people age more healthily.