A surprising health tip recently went viral, suggesting that a simple, cost-free habit could be the secret to a longer life. The claim, which spread online after US tech entrepreneur Bryan Johnson shared it, stated that women who sleep naked could live up to seven years longer. This sparked widespread curiosity and debate about the potential link between nighttime attire and longevity.
The Viral Claim and the Scientific Reality
The original post retweeted by Bryan Johnson argued that cooling the body triggers deeper sleep. It explained that clothing traps heat, creating a warm environment that slows sleep onset, while cooler rooms promote faster and more restorative rest. The post further suggested that in cool sleep, melatonin levels rise, aiding sleep cycles and supporting the body's defences against cellular ageing.
However, Johnson himself labeled the core longevity claim as false. He clarified that while sleeping naked does offer some real benefits, no scientific evidence links it directly to a longer lifespan. "No long term epidemiological or clinical studies have ever linked sleeping naked to increased human lifespan," he emphasized. To put things in perspective, he noted that even completely curing cancer would only increase average life expectancy by about two to three years, making a seven-year extension from sleep habits seem highly exaggerated.
What Does the Research Actually Say About Sleep and Temperature?
Scientific studies confirm a strong connection between body temperature and sleep quality, but not directly with lifespan. A 2012 review published in the Journal of Physiological Anthropology found that heat exposure increases wakefulness and reduces both slow-wave sleep and REM sleep. It established that the thermal environment is a key determinant of sleep because the body's thermoregulation system is closely tied to sleep mechanisms.
Further evidence comes from a 2007 study in the journal Sleep. This controlled human experiment discovered that lowering and delaying the nocturnal core body temperature minimum increased the duration of slow-wave sleep (SWS), which is considered the most restorative phase. The research concluded that increasing passive heat loss during sleep positively affects sleep structure.
A 2025 synthesis by the Sleep Foundation also supports the idea that sleeping naked may help regulate body temperature, potentially improving sleep quality by preventing overheating. It acknowledges that cooler conditions can support deeper, more restful sleep and notes potential intimacy benefits from skin-to-skin contact with a partner, which can boost oxytocin levels.
Specific Benefits and Important Caveats
While not a longevity miracle, sleeping without clothes can offer specific, evidence-based advantages for some individuals. For men, keeping the testes cooler is associated with better sperm quality and fertility markers. For women, improved airflow and ventilation may reduce the risk of genital yeast infections. The practice can also reduce friction, moisture, and skin irritation, enhancing overall comfort.
Despite these points, experts like those at the Cleveland Clinic state there is no proven specific benefit or harm from sleeping nude regarding lifespan. Research in animal models, where lower body temperature sometimes correlates with extended life, does not translate directly to humans in everyday sleeping conditions due to our complex genetics and physiology.
The final verdict is clear: the claim that sleeping naked extends life by seven years is false. The validated benefits are related to sleep quality, not longevity. High-quality sleep, achieved through a cool environment (ideally between 15-19°C or 60-67°F) and good sleep hygiene, supports overall health. This, in turn, can indirectly influence longevity by reducing the risk of conditions like diabetes, heart disease, and obesity linked to poor sleep.
Note: The information provided in this article is for educational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional for personal health decisions.
