Think 8 hours is a good night’s sleep? Science says that number might actually be lower

Think 8 hours is a good night’s sleep? Science says that number might actually be lower

May 26, 2026 discoverhiddenusacom Health

The common advice to aim for eight hours of sleep per night may be outdated. Recent research from the Columbia University Irvin Medical Center suggests that the optimal range for health could actually be lower than previously thought.

Study results indicate that individuals who averaged between 6.4 and 7.8 hours of sleep per night demonstrated better functioning of the heart, brain, and immune system.

The Impact of Sleep on Organ Aging

Researchers found that both insufficient and excessive sleep are markers of poorer overall health. Junhao Wen, an assistant professor of radiology at the Vagelos College of Physicians and Surgeons, noted that while previous research linked sleep to brain pathology and aging, this study shows that too much or too little sleep is associated with faster aging across nearly every organ.

To reach these conclusions, the study employed machine learning to analyse data from 500,000 participants in a decades-long U.K. Biobank study. The team developed “aging clocks” to determine if a person’s organs were aging faster than their actual chronological age.

Did You Know? The study utilized machine learning to analyse data from 500,000 participants in the U.K. Biobank study to create “aging clocks” for various organ systems.

The data revealed a clear pattern: accelerated aging was linked to sleep durations of fewer than six hours or more than eight hours per night.

Health Risks of Sleep Imbalance

The research highlighted specific health risks associated with different sleep patterns. Getting too little sleep was linked to chronic conditions, including heart disease, high blood pressure, Type 2 diabetes, and obesity.

Certain conditions were tied to both short and long sleep durations. These include digestive disorders, asthma, chronic obstructive pulmonary disease (an incurable lung disease), and late-life depression.

Expert Insight: Samantha Carter observes that these findings challenge the “one-size-fits-all” approach to sleep. By identifying that different biological pathways may lead to the same outcome—such as late-life depression—for both short and long sleepers, the medical community may need to shift toward more personalized sleep health strategies rather than prescriptive hourly targets.

Gender Differences in Sleep Needs

The study also suggested that sleep requirements may vary by gender. Marie-Pierre St-Onge, a professor at Columbia University, observed that women appeared to benefit from slightly more sleep than men.

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Specifically, women seemed to do better with an additional 15 to 20 minutes of sleep. This aligns with general population trends and self-reported data, which are often attributed to hormones and a higher risk of sleep disorders.

Future Implications for Sleep Health

Because every individual is different, Junhao Wen emphasized that these results should not be viewed as prescriptive. However, they may suggest a need for experts and patients to alter their approach to sleep health.

Future clinical approaches could potentially treat long and short sleepers differently, as they may be experiencing different biological processes that lead to similar health complications.

Frequently Asked Questions

What is the optimal amount of sleep for heart and brain function?
According to the study, people who slept between 6.4 and 7.8 hours a night had better functioning immune systems, brains, and hearts.

What are the risks of sleeping fewer than six hours a night?
Too little sleep was associated with accelerated organ aging and chronic diseases such as high blood pressure, heart disease, obesity, and Type 2 diabetes.

Do women require more sleep than men?
The research suggests women may do better with about 15 to 20 minutes more sleep than men, which matches general population trends.

Do you prioritize a strict eight-hour window, or do you adjust your sleep based on how you feel?