Sleep

Not a waste of time

Adequate sleep is necessary not only for daily function but for optimal health and wellness. Sleep disturbances can include: difficulties falling asleep, awakening throughout the night, sleep deprivation and sleep apnea (a sleep disorder characterized by pauses in breathing during sleep). We have all experienced the bad mood, fatigue or lack of focus following a poor night’s sleep. Insufficient sleep on a regular basis is associated with long-term health consequences.

Chronic sleep deprivation may affect metabolism and lead to weight gain. People who habitually sleep less than six hours per night are more likely to have a higher body mass index (BMI) than people who sleep eight hours a night. During sleep, our body secrets hormones that control energy, metabolism, appetite and glucose processing. For example, cortisol levels rise with poor sleep leading to increased appetite and deposition of fat around the abdominal area. The gain in weight ultimately results in elevated insulin levels, a hormone that regulates glucose and promotes fat storage, which can increase the risk of developing diabetes.

Alterations in one’s sleep pattern causes an imbalance of hormone levels including leptin and ghrelin.  Leptin is responsible for alerting the brain when the stomach is full while ghrelin stimulates appetite. An inadequate amount of sleep lowers leptin and increases ghrelin causing food cravings to occur shortly after a meal and adding to excess consumption of calories. The combined effect on the metabolism from these two important hormones lead to further complications including obesity, type II diabetes, high blood pressure, heart disease and a shortened life expectancy.

Chronic sleep issues have been correlated with depression, anxiety and decreased memory function. Memory consolidation is a process that occurs during sleep and ensures that new memories are stored. Impatience, irritability, decreased concentration and lowered immune function typically occur following lack of sleep. It is important to maintain a proper balance of sleep per night as too much sleep can also lead to poor health.

Diet and certain lifestyle factors can affect sleep. For example, caffeine in coffee, tea and soft drinks can block receptors that trigger sleep for up to 6-8 hours. Other stimulants can keep you awake. Nicotine can cause lighter sleep. Alcohol is a sedative that can prevent deep sleep or reaching rapid eye movement (REM) sleep (the dream stage of sleep). Large meals or exercise prior to bedtime can create difficulties in falling asleep. Conversely, exercise at night delays the release of melatonin which helps the body to fall asleep, while exercise during the day can actually improve the quality of sleep. Bright lights, television, computer and other noise distractions affect a good night’s sleep. An uncomfortable mattress and pillow decreases your ability to fall and stay asleep.

There is a clear relationship between sleep and our ability to function during the day. The implications of getting sufficient sleep on a regular basis are essential to health and healing. Research suggests that 8 hours of sleep is optimal.

References:

  1. Harvard Medical School Health Publications: http://www.health.harvard.edu/press_releases/importance_of_sleep_and_health
  2. US Department of Health and Human Services: http://www.nhlbi.nih.gov/health/public/sleep/healthy_sleep.pdf