Some individuals, known as natural short sleepers, can function optimally on just 3-4 hours of sleep due to genetic mutations that alter their sleep architecture, challenging the universal sleep recommendations and offering potential insights for treating sleep disorders. However, this trait is rare and not something that can be acquired through lifestyle changes, with most people needing 7-8 hours for health and cognitive function.
A study analyzing UK Biobank data found that "short sleepers" who sleep less than 6 hours daily without experiencing daytime sleepiness tend to have larger brain volumes compared to short sleepers with daytime sleepiness and individuals who sleep longer durations. However, short sleepers generally have slightly lower cognitive functioning than those who sleep the recommended 7-8 hours. The study highlights the importance of sleep for brain health and cognitive function, but also notes that there are individual differences in sleep needs due to genetic and environmental factors, making general recommendations about sleep duration challenging.
