Think eight hours of sleep is the gold standard? A new study suggests the optimal range might actually be lower, between 6.4 and 7.8 hours per night. Researchers at Columbia University Irving Medical Center found that people sleeping within this range had better functioning immune systems, brains, and hearts.
Study Details
The study, published recently, analyzed data from 500,000 participants in the UK Biobank using machine learning to detect signs of aging in organs. Researchers developed 'aging clocks' to compare organ age with chronological age. They found that sleeping fewer than six hours or more than eight hours was associated with accelerated aging across nearly every organ.
Key Findings
- Optimal sleep: 6.4-7.8 hours per night
- Too little (<6 hours) linked to chronic diseases like obesity, type 2 diabetes, high blood pressure, and heart disease
- Both short and long sleep tied to asthma, digestive disorders, late-life depression, and COPD
Junhao Wen, assistant professor of radiology at Columbia, explained: 'Previous studies found sleep linked to brain aging. Our study shows too little and too much sleep are associated with faster aging in nearly every organ.' He emphasized that sleep is crucial for maintaining organ health.
Gender Differences
Women appeared to need slightly more sleep than men. Marie-Pierre St-Onge, a Columbia professor not involved in the study, told The Washington Post: 'Women seem to do better with a little longer, about 15-20 minutes. This matches what we see in self-reported sleep duration.' This aligns with past research citing hormonal differences and higher risk of sleep disorders in women.
Implications
The findings challenge the common 'eight hours' rule. Wen noted: 'Our study suggests different biological pathways between long and short sleepers leading to the same outcome, like late-life depression. We shouldn't treat them the same way.' He cautioned that the results are not prescriptive, as individual needs vary.
Too little sleep was also associated with chronic conditions, while both extremes were linked to respiratory and mental health issues. The research underscores the importance of personalized sleep health.
