The Importance of Sleep
The quality of sleep has an enormous impact on daily life, since poor or disordered sleep can affect your work, concentration, and ability to interact with others. During sleep, both physical and mental restoration take place, allowing you to feel fresh and alert in the morning.
Sleep needs vary from one person to another; the optimal average is 7 to 9 hours. You can judge whether or not you’re getting the right amount by how you feel the next day — too much or too little sleep leaves a person feeling tired and irritable. Because growth hormones are released during sleep, babies, children, and adolescents require more sleep than adults do.
Sleep researchers discount the common myth that older people require less sleep; instead, the amount of sleep that an adult needs remains fairly constant. With advancing age, however, the nature of sleep changes and the incidence of sleep disorders rises. The degree of time spent in the deeper stages of sleep often lessens with age, and an older person is likely to awaken more frequently during the night.
This is still not fully understood, but scientists know that a person’s circadian rhythm is established shortly after birth and is then maintained as a “body clock.” Some natural chemicals in the body enhance sleep, and diet plays a part. Here are some things that are known to affect sleep:
- Eating too much or too little can disrupt sleep. A light snack at bedtime can promote sleep, but too much food can cause digestive discomfort that leads to wakefulness.
- Alcohol is a double-edged sword. Small amounts of alcohol can help you fall asleep. However, as the body metabolizes the alcohol, sleep may become fragmented. Alcohol can worsen insomnia and also impair rapid eye movement (REM) sleep, the time when the body is in its restorative phase. It can also dehydrate you, leaving you tired the next day.
- Caffeine can disturb sleep. Any food or beverage that contains caffeine can disturb sleep, although this is not true for everyone. Research has shown that older adults who suffer from insomnia report higher caffeine intakes. If you are sensitive to caffeine, avoid it in the afternoon and evening.
- Forget the fat. If you consume a high-fat meal in the evening or eat foods that you have found cause you indigestion and heartburn, your sleep can be disturbed and restless.
- Do not eat late at night. People who suffer from heartburn or acid reflux should avoid late, heavy meals that delay the emptying of the stomach. Lying down with a full stomach puts you at a gravitational disadvantage, encouraging acids and gastric juices to flow up into the esophagus, causing uncomfortable heartburn that will make sleep more challenging.
- Drinking fluids too close to bedtime can cause problems. Avoid fluids after dinner to reduce the need to go to the bathroom during the night.
- Milk and honey promote sleep. Milk contains tryptophan, an essential amino acid that is among the natural dietary sleep inducers. Tryptophan works by increasing the amount of serotonin, a natural sedative, in the brain. This is why so many folk remedies include warm milk with a teaspoonful of honey, a simple sugar. (Carbohydrates facilitate the entry of tryptophan into the brain.) A turkey sandwich provides another sleep-inducing combination of tryptophan and carbohydrates. A banana with milk gives you vitamin B6, which helps convert tryptophan to serotonin.
Many herbs are said to be useful for inducing sleep; one of the most popular and reliable is valerian. Its qualifications as a sedative have been supported by research demonstrating that active ingredients in the valerian root depress the central nervous system and relax smooth muscle tissue. Valerian that is brewed into a tea or taken as a capsule or tincture can lessen the time it takes to fall asleep and produce a deep, satisfying rest. It does not result in dependency or cause a “hungover” feeling. Valerian is not recommended for use during pregnancy or breast-feeding, since it has not been studied for these conditions. Other herbal remedies that have been suggested for sleep problems include teas made of chamomile, hops, lemon balm, and peppermint, but there is not much evidence that they work.
The Role of Melatonin
A hormone produced by the brain, melatonin is instrumental in regulating the body’s sleep-wake cycle. Researchers think that it may control the onset of puberty, a woman’s menstrual cycle, mood, and the release of growth hormones. Melatonin can alleviate insomnia, although in some cases it has caused disturbed sleep (melatonin supplements are available in the United States, but their sale is not allowed in Canada). When taken correctly, it may prevent jet lag, but the many other claims for melatonin — for example, that it can prevent cancer, boost immunity, and forestall aging — are unproved.
Melatonin appears to be safe when it’s taken in small amounts to overcome a temporary bout of insomnia. But experts caution against taking large doses or long-term use because of melatonin’s potential side effects, which include grogginess, depression, and sexual dysfunction. Melatonin should not be taken by women who are attempting to conceive, pregnant, or breast-feeding; nor should it be administered to children or used by anyone with severe allergies, mental illness, rheumatoid arthritis or other autoimmune diseases, and lymphoma and certain other types of cancers.