Study: Excessive Sleep Increases Risk of Mortality
Sleep is an essential biological function, necessary for physical and mental recovery. Quality sleep in sufficient quantity is widely recognized for its health benefits, including metabolic regulation, improved cognitive functions, and prevention of many chronic diseases. However, a recent study has drawn attention to the risks associated with so-called “excessive” or “prolonged” sleep. This phenomenon, often less discussed than sleep deprivation, may have serious detrimental effects, notably an increased risk of mortality.
Background and Objectives of the Study
The study, conducted by an international team of researchers and published in a reputable scientific journal, relies on extensive epidemiological data from several countries. The primary objective was to examine the association between sleep duration and all-cause mortality, with a particular focus on risks related to prolonged sleep, generally defined as sleeping more than nine hours per night.
Methodology and Sample
Researchers analyzed data from several cohorts totaling tens of thousands of participants aged between 40 and 79, followed for an average period of ten years. Sleep durations were self-reported by participants, which represents a methodological limitation, but the findings are significant and consistent with previous studies.
Statistical analyses accounted for various confounding factors such as age, sex, body mass index, smoking status, physical activity, and medical history. This rigor allows for isolating the effect of sleep duration on mortality risk.
Main Results
The results reveal a characteristic U-shaped curve, where mortality risks are elevated both for short sleepers (less than six hours) and for excessive sleepers (more than nine hours). Specifically, prolonged sleep is associated with a 20 to 30 percent increased risk of death compared to an optimal sleep duration of seven to eight hours per night.
The main causes of death linked to excessive sleep include cardiovascular diseases, metabolic disorders such as diabetes, and certain cancers. This relationship may be explained by still poorly understood pathophysiological mechanisms, though several hypotheses have been proposed.
Explanatory Hypotheses
Prolonged sleep could be a symptom of an underlying health condition, such as chronic inflammatory disorders, depression, or undiagnosed pathologies affecting sleep quality and recovery. Furthermore, excessive sleep might disrupt circadian rhythms and lead to hormonal imbalances, notably involving cortisol and melatonin, which could promote disease development.
Additionally, excessive sleep may reduce physical activity, leading to a sedentary lifestyle—a well-known risk factor for increased mortality.
Public Health Implications
These findings call for a reconsideration of the traditional focus solely on sleep deprivation. Healthcare professionals must now raise awareness about the risks of prolonged sleep and encourage a balanced approach. It is important to assess not only sleep duration but also sleep quality, to identify disorders that may explain hypersomnia.
Moreover, prolonged sleep should prompt a thorough medical evaluation to detect possible underlying diseases.
Practical Recommendations
To maintain good health, experts generally recommend sleeping between seven and eight hours per night, adjusted to individual needs. Adopting strict sleep hygiene, avoiding excessively long naps, maintaining regular physical activity, and consulting a specialist in cases of persistent fatigue are essential pieces of advice.
Conclusion
This study highlights that while sleep is vital, it can become a risk factor when excessive. Awareness of the negative effects of prolonged sleep is crucial for disease prevention and the promotion of a balanced lifestyle. Future research should deepen the understanding of the underlying mechanisms and help develop personalized recommendations to optimize health through healthy and adequate sleep.
