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Cómo Dormir Bien: Para Comprender la Importancia del Descanso y la Salud Optima
For the past 25 years, Americans have been sleeping less and less each night. In surveys conducted by the National Sleep Foundation, up to 69% of adults report having sleep problems on a few nights a week or more. Insomnia is, by far, the most common sleep disorder in the United States, affecting nearly 70 million of us; 35% of survey respondents had insomnia every night and nearly 60% reported insomnia at least a few nights per week.
Sleep was first described physiologically in the 1930s and our understanding was greatly enhanced by the discovery of rapid eye movement (REM) in the 1950s. Our sleep is usually divided into various phases, based on the differences in brain activity throughout the night. During these phases, our bodies repair and our memories are organized.
While the exact reasons for why we need sleep are still unknown, what is clear is that chronic poor sleep can have serious health consequences. There is growing evidence to suggest that there is a deeper, more reciprocal relationship between sleep and immune function than previously thought.
SLEEP AND THE IMMUNE SYSTEM
When we get sick, we tend to feel tired and sleep more. But is this coincidental or is sleep a recuperative immune function? One study showed that infected rabbits that slept more had a better prognosis, suggesting that sleep might enhance illness recovery. But it’s unclear whether other factors, such as stress, might have been the cause of disrupted sleep in the rabbits that didn’t fare so well.
And in humans, there’s an increasing amount of research evidence that suggests that the right amount of sleep might prolong life; one study of elderly patients found that poor quality sleep was significantly associated with mortality.
Additionally, several studies have demonstrated that sleep deprivation can cause changes in immune-cell functional activity. In one study involving tumor growth in rats, tumor size reached its peak more quickly in sleep-deprived animals.
As more research is conducted on this subject, it is hoped that the exact nature of the relationship between sleep and the immune system’s role in controlling tumor growth and size can be ascertained.
CHRONIC VERSUS ACUTE SLEEP LOSS
While chronic sleep loss has been shown to be harmful to well-being, there’s growing evidence that the occasional acute sleep disturbance might actually boost the immune system.[5,6,7]
In a study involving sleep-deprived rats,the animals’ ability to defend against infection was dependent on the length of their sleep depravation. Evolutionarily, it may be that the immune system needs to be enhanced by brief total sleep loss, such as when being hunted by a predator. But without sleep, the immune system does eventually fail.
HOW TO SLEEP BETTER
What constitutes “good” sleep is highly subjective,but most people would agree that an evening of high quality sleep is one in which you’re able to fall asleep quickly, stay asleep throughout the night, and wake up feeling refreshed.To achieve this sort of sleep, there are several approaches, from behavioral to pharmacological.
COGNITIVE AND BEHAVIORAL APPROACHES
In several systematic reviews, it has been suggested that “behavioral interventions appear to be as effective as pharmacotherapy in the short term”[22,23,24] and, in some cases, “are reported as superior in the long term.”
» Music: A recent study from researchers in Taiwan found that people who listened to soft,slow music at bed time “experienced physical changes that aided restful sleep, such as lower heart and respiratory rates.” Participants listened to 45-minute sedative music tapes at bedtime for three weeks. The study found that this resulted in “significantly better sleep quality” and that “sleep improved weekly, indicating a cumulative dose effect.”
» Yoga: A recent study showed that participants who attended regular yoga sessions reported “significantly lower sleep disturbance” as compared to a control group.This included better overall quality of sleep, ability to fall asleep quicker, longer sleep duration, and less use of sleep medications.
See “Sleep Hygiene Tips” below for other non pharmacological strategies for a better night’s sleep.
PHARMACOLOGICAL APPROACHES: MELATONIN
Melatonin was first isolated roughly 50 years ago[11,12] and is a chemical that has been functionally linked to the body’s regulation of circadian and seasonal rhythms, immune function, and tumor inhibition. Melatonin is not a hypnotic or soporific but rather seems to function as a chemical that “opens the gate” to sleep, not something that induces sleep itself.
Melatonin production takes place in the brain and is mostly regulated by ambient light; only during darkness does the majority of melatonin production take place. The amount of melatonin an individual produces is also genetically determined, but age can also be a factor as people tend to produce less melatonin as they grow older.
MELATONIN AND CANCER
In addition to promoting sleep, which can, in turn, help the immune system, melatonin may also have properties that can help prevent cancer by scavenging free radicals (which can damage DNA) in the body or retard tumor growth once cancer starts, prolonging survival when combined with conventional cancer therapy. While much of this research has only taken place in animal studies,[10,18] newer studies involving humans have produced encouraging results.
In a randomized study of 450 advanced cancer patients with poor clinical status or chemotherapy-resistant tumors, “melatonin seemed to enhance tumor response rate, prolong survival time, and prevent chemotherapy-induced neurotoxicity.” Because we naturally produce less melatonin as we age, the lack of this chemical may also contribute to the increased frequency of cancer in the elderly. And while melatonin is not a ‘cure’ for cancer, its properties certainly warrant further study.
PHARMACOLOGICAL APPROACHES: OTHER DRUGS
One of the fastest growing segments of the drug market is prescription sleep aids. These drugs are generally effective in making it easier to fall asleep, stay asleep, and increase total time asleep. There are, however, adverse effects to consider, such as dependency, withdrawal, and tolerance.
The World Health Organization defines drug dependence as” the development of an altered physiological state which requires continued administration of a drug” to prevent withdrawal symptoms. Withdrawal symptoms are generally defined as those that start after a drug is discontinued or reduced (i.e. symptoms not present before treatment). Tolerance is defined as a decrease in a drug’s effect with continued administration, which results in the need to increase the dose of the drug.
Sleep Hygiene Tips
SLEEP ONLY WHEN SLEEPY This reduces the time you’re awake in bed. If you can’t fall asleep within 20 minutes, get up and do something boring until you feel sleepy. Avoid bright light during this time.
DON’T TAKE NAPS This will help make you tired at bedtime. If you must nap, sleep for less than an hour before 3pm.
GO TO BED ON TIME Get up and go to bed the same time every day, even on weekends. It’s easier to sleep when you have a regular sleep cycle.
TIME YOUR EXERCISE Regular exercise can help improve your sleep, but don’t do so too close to bedtime (at least 4 hours).
DEVELOP SLEEP RITUALS It is important to give your body cues that it is time to sleep, such as listening to relaxing music, drinking herbal tea, or meditating.
ONLY USE YOUR BED FOR SLEEPING Refrain from using your bed to watch TV, pay bills, do work, or read.
AVOID CAFFEINE, NICOTINE, AND ALCOHOL Caffeine and nicotine are stimulants and alcohol can cause poor, fragmented sleep. Avoid them all for at least 4 hours before bedtime.
HAVE A LIGHT SNACK BEFORE BED Sleeping on too empty or too full a stomach can interfere with sleep.
TAKE A HOT BATH While a hot bath 90 minutes before bedtime will raise your body temperature, the drop in temperature afterwards may make you feel sleepy.
COOL YOUR ROOM Sleeping in too hot an environment can be difficult. A cooler room, at a sleep-promoting 65 degrees with enough blankets to stay warm, is recommended.
KEEP THINGS DARK AND QUIET Blackout shades or an eye mask can help block out light and earplugs or a white noise machine can help reduce noise.
RESET YOUR BIOLOGICAL CLOCK As soon as you get up in the morning, go outside and turn your face to the sun for 15 minutes.
Adapted From: How to Sleep Well
More on Melatonin
Melatonin has been shown to “open the gates” to sleep, so timing is very important depending on the desired effect.
IN GENERAL: Bright light exposure after darkness onset at night should be avoided since it disrupts the melatonin rhythm and alters the circadian clock. When used for night-time sleep promotion, melatonin is best taken 30 minutes before desired sleep onset.
WHEN TAKEN AT 8PM: Melatonin advances the internal clock, making you feel like it’s later than it really is. Dosage for sleeping is 1 to 5 mg.
WHEN TAKEN AT DAWN: Melatonin delays the internal clock, making you feel like it’s earlier than it really is. Dosage for dawn is 1 mg.
TAKING MELATONIN WHEN TRAVELING EAST: If you were traveling from San Francisco to Paris, take melatonin at dusk San Francisco time (which may be on the plane). Then take melatonin at dusk Paris time when you’ve arrived. A day or so before heading home, take melatonin at dusk Paris time and then, once home, at dusk San Francisco time.
TAKING MELATONIN WHEN TRAVELING WEST: If you were traveling from San Francisco to Beijing, take melatonin once you arrive at dusk Beijing time. Before you leave, take melatonin at dusk Beijing time and then, once home, at dusk San Francisco time. Note: It has been suggested that westbound travel causes less jet lag and that melatonin is not very effective for westbound travel of less than four time zones.
NEGATIVE DRUG INTERACTIONS TO CONSIDER: Anticoagulant and Antiplatelet Drugs, Antidiabetes Drugs, Benzodiazepines, Caffeine, CNS Depressants, Contraceptive Drugs, Flumazenil (Romazicon), Fluvoxamine (Luvox), Immunosuppressants, Nifedipine GITS (Procardia XL), Verapamil (Calan, Covera, Isoptin, Verelan).
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