The Ideal Amount of Sleep: A New Perspective
We’ve all heard the phrase “make sure to get eight hours of sleep” — but recent research shows that the optimal range of shut-eye could be lower than you might think. People who got between 6.4-7.8 hours of sleep a night were found to have better functioning immune systems, brains, and hearts, according to researchers at the Columbia University Irvin Medical Center.
The findings suggest that getting too little or too much sleep are hallmarks of poorer overall health. Junhao Wen, an assistant professor of radiology at the school’s Vagelos College of Physicians and Surgeons, explained in a release that previous studies have found sleep is largely linked to aging and the pathological burden of the brain. However, this study goes further and shows that too little and too much sleep are associated with faster aging in nearly every organ.
This supports the idea that sleep is important in maintaining organ health, he noted. Women included in the study appeared to need more sleep than men, according to Marie-Pierre St-Onge, a professor at Columbia University who was not involved in the study. She told The Washington Post that women seem to do better with a little longer sleep — about 15, 20 minutes. This matches what we see in the general population and self-reported sleep duration, which tends to be slightly longer in women than men.
That builds on years of past research drawing similar conclusions, citing hormones and an increased risk of sleep disorders.
Ticking Clocks
The study used machine learning to detect signs of aging organs in 500,000 participants of the decades-long U.K. biobank study. The hypothesis is that different organs, even within the same person, age at different rates, Wen told The Washington Post.
Researchers developed what are known as “aging clocks,” which show if a person’s organ is aging older than their actual age. They created dozens of clocks for organ systems throughout the body to see if the aging was linked to sleep. That’s when they noticed the pattern: too much or too little sleep was associated with accelerated aging. Too little was fewer than six hours a night, and too much was greater than eight hours.
The Health Impacts of Sleep Duration
Too little sleep was associated with chronic disease, such as obesity, Type 2 diabetes, high blood pressure, and heart disease. Both short and long sleep were tied to asthma, digestive disorders, late-life depression, and chronic obstructive pulmonary disease, an incurable lung disease, the research found.
That suggests patients and experts should potentially alter how they think about sleep health going forward, Wen said. Although he pointed out that the study’s results should not be prescriptive, and every body is different.
“Our study suggests there may be different biological pathways between long and short sleepers that lead to the same outcome, late-life depression, and we shouldn’t treat them the same way,” he said.
