A recent Australian study reveals that the regularity of sleep may be more important than the total hours slept. Researchers found that going to bed at the same time every night reduces the risk of death more effectively than simply sleeping longer. During the study period, individuals with consistent sleep schedules had a 20%–48% lower risk of all-cause mortality compared to those with irregular sleep. Those with the most regular sleep patterns also had a 16%–39% lower risk of dying from cancer, and a 22%–57% lower risk of death from cardiovascular or metabolic diseases.
Dr. Huang Wen-Qian, a neurologist at Changhua Show Chwan Memorial Hospital, explained that regular sleep helps stabilize the body’s biological clock, ensuring more consistent hormone release. However, he emphasizes that sleep duration still matters: sufficient hours are needed to achieve deep sleep, which clears toxins and metabolic waste from the brain, potentially lowering the risk of dementia over time.
Dr. Zhang Meng-Han, a psychiatrist at Tung Yuan General Hospital, notes that while previous research emphasized total sleep hours—recommending 7–8 hours per night for adults—recent studies highlight the importance of sleep regularity as well. People with irregular sleep-wake patterns are at increased risk of cardiovascular issues due to disrupted circadian rhythms.
Dr. Lü Zong-Hua of Cheng Kung Hospital adds that the body operates like an orchestra directed by the “conductor” of the biological clock, located in the hypothalamus. Light cues guide the sleep-wake cycle, body temperature, hormone secretion, and metabolism. Modern lifestyles—late-night screen time, shift work, and inconsistent weekend sleep—can disrupt this rhythm, leading to a “social jetlag” effect.
Neurologist Dr. Li Gang-Bo of Kaohsiung Show Chwan Memorial Hospital also emphasizes that recent studies show sleep regularity can sometimes be more crucial than sleep length. Maintaining a consistent bedtime and wake-up schedule significantly lowers mortality rates and reduces risks for hypertension and metabolic diseases.
Harvard Medical School research supports these findings, showing that even individuals who sleep eight hours a night but have irregular schedules experience worse metabolic outcomes, including reduced insulin sensitivity, blood sugar fluctuations, weight gain, and elevated cardiovascular risk.
Dr. Lü adds that inconsistent sleep, like catching different “flights” every night, can cause daytime fatigue, poor focus, mood swings, and over time, increase the risk of obesity, diabetes, hypertension, and depression.
Experts agree that while occasional late nights are unavoidable, keeping a stable bedtime and wake-up routine is essential for maintaining a healthy circadian rhythm. Dr. Zhang reminds readers: “Sleeping longer doesn’t automatically mean healthier sleep. Regular sleep patterns are the real key to balance the body and mind, ensuring wakefulness during the day and restorative sleep at night.”
