We all want to get a good night's sleep and wake up feeling refreshed. But, too often, it seems we're left staring at our ceilings at 3 am, wondering why our minds won't shut off, or we will get a full night's sleep but wake up still feeling exhausted. Several things could be causing these terrible periods of sleep; addressing the underlying cause and adopting positive sleep hygiene habits can help.
What Interferes with Getting a Night of Good Sleep?
We recently discussed the complex relationship between sleep and stress. Not only can stress result in poor sleep, but a lack of sleep or poor quality sleep can also negatively affect the body's stress response.
Caffeine and Alcohol
While most people have their cup of joe in the morning, it may be tempting to have one more shot of caffeine in the afternoon to help get through the day — especially if you're tired from a poor night's sleep. But a study in the Journal of Sleep Medicine found that caffeine intake even six hours before bedtime has significant disruptive effects on sleep, reducing sleep by more than one hour (1). The study suggests restricting caffeine consumption to no later than before 5:00 pm (1). However, if you have an early bedtime, you may want to restrict caffeine even earlier. (Don’t forget that chocolate has caffeine, so it may be best to avoid it after dinner.)
It is also interesting to note that specific genes affect how quickly you metabolize caffeine. Those that metabolize it quickly may get away with consuming more caffeine later in the day. However, for slow metabolizers, just a small amount can affect them up to nine hours later - and the more they consume, the longer it takes to clear their system.
Although alcohol provides sedative effects that can make you feel relaxed and sleepy, it's linked to reduced sleep quality and can exacerbate sleep apnea symptoms (2). The effects of alcohol on sleep vary by individual but, according to a 2018 study, low amounts of alcohol (less than two drinks per day for men and less than one drink for women) decreased sleep quality by 9.3%, while moderate amounts of alcohol (two servings for men and one serving for women) decreased sleep quality by 24% and high amounts (more than two drinks for men and one for women) decreased sleep quality by 39.2% (3).
While loud noises and sleeping in an unfamiliar place are obvious culprits for poor sleep, blue light is also a top offender. Sources of blue light include computer and phone screens and fluorescent and LED lighting. Harvard researchers found that blue light suppresses melatonin secretion twice as long and shifts circadian rhythms twice as much as green light (4). Harvard Medical School suggests the following for blue light protection at night (4):
Use dim red lights for night lights, which are less likely to suppress melatonin and shift circadian rhythm.
Avoid looking at a bright screen two to three hours before bed.
Night shift workers or those that use electronic devices at night should consider blue-blocking glasses or installing an app that filters the blue/green wavelength at night.
Bright light exposure during the day can boost sleep at night.