Can You Sleep Too Much (Or Too Little)?
“Sleep is that golden chain that ties our health and our bodies together.” – Thomas Dekker
I used to think you could never get too much sleep. Of course, that was years ago when I was chronically sleep deprived due to working full-time, going to college at night, raising my kids as a single mom, and trying to have some sort of social life when they were with their other parent. Turns out, there’s a growing body of research that points to the negative effects of either too much or too little sleep.
Too little or too much sleep can affect metabolic health.
Concerned about an expanding waistline? Prone to getting less sleep or more than you need? There’s scientific basis for the link between too little and too much sleep and metabolic syndrome and increasing waistlines in Korean men and women aged 40-69 years in one recent study. Researchers said the study’s observational nature did not allow for cause and effect conclusions, noting that participants provided sleep duration data and estimates may reflect time in bed and not necessarily time slept. Other studies have reported that short-duration sleepers (less than 5 hours per night) are up to 45 percent more likely to be obese.
Excessive and inadequate sleep can affect memory and cognition.
Chronically sleep-deprived people, says Harvard Health Publishing, are more likely to have high blood pressure, narrowed blood vessels, and diabetes – each of which cause less blood flow inside the brain. Since the brain requires a good flow of oxygen and sugar to work optimally, too little sleep can contribute to memory problems. Those who get too much sleep, on the other hand, aren’t off the hook memory-wise as their quality of sleep may suffer, which could add to thinking and memory problems during the day.
Excessive daytime sleepiness can be particularly troubling for older adults. Researchers found that cognitive deficits and cognitive impairment may be predicted by excessive daytime sleepiness among the elderly. Excessive sleepiness, or hypersomnolence, has two main symptoms: excessive amount of sleep, and poor quality of awakening. Hypersomnolence is the leading cause of road accidents, and is responsible for increased risk of mortality related to neurodegenerative diseases.
If you’re an early riser, you may be less prone to depression.
Researchers are delving into pertinent data showing that middle-aged to older women who get up early may be significantly less likely to develop depression. The largest observational study to-date looks at the link between chronotype (also known as sleep-wake preference) and mood disorders. Researchers found that, even after accounting for such factors as work schedules and light exposure, chronotype, partly influenced by genetics, seems to have a mild influence on depression. The four-year study involved nearly 33,000 female nurses who were free of depression at the start of the study. Thirty-three percent self-described their sleep pattern as early-riser, 53 percent intermediate, and 10 percent evening types. After four years of follow-up, researchers found that early risers had 12-27 percent lower risk of depression than intermediate types, while late-riser types had a 6 percent higher risk of being depressed, although this was not considered statistically significant.
One study found that excessive sleep is “highly associated” with dysthymic disorder and major depressive disorder. Those researchers also found that many anxiety disorders are “associated with prolonged sleep episodes accompanied by consequences/distress.”
Better cardiovascular health is associated with early-rise behavior.
More good news for early risers is the apparent association such behavior has on better cardiovascular health. Researchers in the UK Biobank study found that those who are early to bed and early to rise are “more conscientious and are goal-getters.” They also spent less time in front of electronic devices, ate more fruit and vegetables daily than late chronotypes. Survey participants categorized as evening persons also tended to watch more television and were twice as likely to smoke tobacco than intermediate types and 45 percent more likely to smoke than adequate sleepers. Researchers noted that more study is needed to determine if sleep metrics can predict better cardiovascular health behaviors and if sleep behavior modification can enhance heart health.
If you sleep too much, you may have a sleep disorder.
For those who constantly sleep too much, sleeping longer than 8 hours a night, often napping during the day, finding it difficult to stay awake, the underlying cause may be a sleep disorder known as hypersomnia. Besides excessive sleepiness throughout the day not relieved by napping, hypersomnia sufferers may also experience anxiety, memory problems and low energy. The American Sleep Association states that more men than women have hypersomnia, with prevalence at 5 percent of the population. The ASA also reports that 50-70 million adults in the U.S. have a sleep disorder of some kind.
The most common sleep disorder is insomnia, affecting about 30 percent of the adult population with short-term insomnia, and about 10 percent suffering chronic insomnia. Other forms of sleep disorder and sleep-related breathing disorders include, narcolepsy, snoring, and central sleep apnea. Circadian-rhythm sleep disorders include jet lag, shift work, and delayed, advanced, irregular and non-24-hour sleep-wake rhythm. Parasomnias and sleep-movement disorders round out the category of sleep disorders.
Insufficient sleep over a prolonged period can affect your mental and emotional states.
If you’re perpetually sleep-deprived, your brain is exhausted, unable to adequately perform its duties. Besides difficulty concentrating, your brain’s ability to send signals to other parts of your body may be delayed, which could prove fatal when driving, using dangerous equipment, trying to avoid life-threatening situations. Lengthy periods of sleep deprivation can result in other problems with your mental and emotional states, including hallucinations, trigger mania in those with manic depression, or amp up risks of paranoia, depression, impulsive behavior, and suicidal thoughts.
If you suffer from the effects of too much or too little sleep, help is available. Besides tips for getting better sleep, make an appointment to see a sleep professional or your general practitioner to have tests to determine the cause of excessive or insufficient sleep, as well as how to get back to getting the right amount of sleep you need nightly.