Sleep is a period of brain activity that is essential for restorative brain health. It is not only the duration of sleep that is critical but also obtaining the different components of sleep (non-REM and REM/dreaming sleep). Obtaining adequate sleep is essential for daytime cognitive function and the American Academy of Sleep Medicine recommends that adults sleep at least 7 or more hours on a regular basis for best health. (1) During sleep, the brain and body restore energy stores. Insufficient sleep is associated with neuroinflammation and the increased production and decreased clearance of toxic proteins (including amyloid and tau, the substances associated with neurodegeneration and Alzheimer’s Disease). Sleep is essential for attention, learning, and eliminating information that is not needed. REM/dream sleep is suggested to be essential for mood regulation.
Healthy Sleep Habits
It is often possible to improve sleep by following the healthy sleep habits outlined by sleep experts. They include the following:
- Go to bed at the same time and wake up at the same time daily, even if you did not sleep well the night before. This will assist your brain in keeping a diurnal rhythm (regular awake and sleep cycle). Waking up at the same time every day is strongly associated with the regulation of diurnal rhythms.
- Do not spend time in the bed outside of sleep and having sex. Avoid watching TV and reading in bed. You are training your brain that your bed is primarily for sleep. If you are unable to sleep after going to bed and are awake for 30 minutes, get up and read a boring book until you are sleepy. It is important not to look at a bright light when you get up, but rather use a dim light set up behind you for reading.
- Avoid stimulating activities close to bedtime. One study found that people ranging in age from 18 to 94 who used a phone in bed after lights out had a longer delay before falling asleep, poorer sleep, and more daytime dysfunction. (2)
- Follow a regular, relaxing bedtime routine to help teach your body to wind down. Relaxation techniques, mindfulness meditation, (3) a warm bath, and/or soft music may be helpful. Lavender enhances a relaxed state through the compound linalool. (4)
- A dark, quiet, and cool environment promote sleep. Consider blackout curtains or eye masks if needed and white noise to calm and block other noises. Research suggests a bedroom temperature of 65 degrees is best for sleep.
- Daily exercise promotes physical fatigue, decreases stress and assists sleep in addition to its many other health benefits.
Diet and Sleep
Diet and sleep are closely related. Large observational studies have found that people who follow the Mediterranean diet are less likely to have insomnia or reduced sleep duration. Eating foods rich in unsaturated fat such as nuts, olive oil, fish, and avocados improves sleep. An association between poor sleep and diets of simple sugars and highly processed foods has been identified. While eating a healthy diet promotes sleep, poor sleep promotes hunger for junk food. One study showed that restriction to 4 hours of sleep 5 nights in a row resulted in a preference for pizza, doughnuts, and candy, but after 5 nights of normal sleep, the hunger for junk food resolved. While eating carbohydrates may help promote falling asleep faster, more sugar and simple carbs are associated with a tendency to wake up more frequently throughout the night. (5)
Specific foods that may modestly improve sleep include tart cherries (contains the precursor to melatonin, tryptophan), pumpkin seeds (contains magnesium) and parmesan cheese, soybeans (contain tryptophan). (6)
Melatonin, a Natural Sleep Aid
Melatonin is a natural hormone that is made by the pineal gland. Its production follows a 24-hour circadian cycle set by light input on the retina during the day and melatonin release at night. Melatonin begins to increase about 2 hours before usual bedtime and remains up throughout the night, peaking about 2 to 3 hours before usual wake time.
Taking supplemental melatonin can be helpful to promote sleep and maintain sleep. It also has antioxidant and anti-inflammatory properties. Because of the potential variability in products, it is important to obtain a quality formulation. Melatonin is usually well-tolerated and safe, but possible side effects include headache, nausea, dizziness, and drowsiness. A dose of 1 mg to 3 mg taken 2 hours before bedtime is generally recommended. (7, 8) Melatonin has the added benefit of decreasing gastro-esophageal reflux disease (GERD), possibly further improving sleep by this mechanism. (9) The ultimate benefit of melatonin for sleep may take several days as it stabilizes the circadian system. (10)
Blue light that is used on phones, computer screens, and television suppresses melatonin. It is for this reason that the use of electronic devices within a couple of hours of bedtime is discouraged. It may be helpful to use blue light blocking glasses in the later evening.
Following a concussion, insomnia increased awakenings, nightmares, fatigue, and over-sleeping may occur. Melatonin and morning light exposure may improve sleep and assist in the recovery of concussion.
Obstructive sleep apnea is a common disorder that can negatively impact the quality of life and health if left untreated. It is often associated with cognitive complaints and increases the risk of cardiovascular and psychiatric disorders. An apnea episode occurs when a sleeping person stops breathing for 20 to 30 seconds at a time due to the closure of the airway. The abnormal breathing pattern occurs repetitively during the night and is associated with lowered oxygen levels and sleep disruption. Risk factors include snoring, obesity, an enlarged neck circumference, and/or a receding chin line. Associated complaints include excessive daytime sleepiness, morning headaches, and high blood pressure. (11) If excessive daytime sleepiness is occurring driving should cease until the disorder is evaluated and treated. (12) It is important that anyone suspected of having sleep apnea avoid sedatives and alcohol because these substances relax the airway and may dangerously worsen the apnea. A standardized sleep study of the breathing pattern is required to define the sleep-related breathing disorder. This condition is treatable. Possible treatment options may include weight loss, limiting sedatives, avoiding sleeping on the back, and wearing a CPAP breathing assist apparatus when sleeping. CPAP is the gold standard treatment and provides an airway splint through air pressure that prevents snoring and apneas. (13)
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