It may seem obvious that sleep is beneficial; what with the fact that going without sleep for too long makes us feel terrible. Getting a good night's sleep can make us feel ready to take on the world.
Experts say that in studies of humans and other animals, they have discovered that sleep plays a critical role in immune function, metabolism, memory, learning, and other vital functions.
Sleep specialist/assistant professor of psychiatry at the Harvard Medical School, Dr. Robert Stickgold, whose work focuses on the nature and function of sleep, notes that sleep plays an important role in memory, both before and after learning a new task.
He warns that lack of adequate sleep affects mood, motivation, judgment, and perception of events.
As important as sleep is, however, experts warn that the positions we assume when we sleep – whether as adults or as children – can affect our health in ways we don't imagine.
A study led by a researcher from the University of Michigan School of Public Health and published in the International Journal of Gynaecology and Obstetrics, reveals that pregnant women who slept on their back (supine sleep) increased the risk of low birth weight by a factor of five, and that it was the low birth weight that explained the high risk for stillbirth in the affected women.
The study's senior author, Dr. Louise O'Brien, an associate professor in the institution's Sleep Disorders Centre, says "though this study was conducted in a maternity hospital in Ghana, which has high perinatal mortality, a recent case-control study from New Zealand also found a link between maternal supine sleep and stillbirth."
She argues that the possibility that supine sleep has a part in low birth weight and, subsequently, stillbirth, is plausible "because of uterine compression on the inferior vena cava, resulting in reduced venous filling and cardiac output."
A consultant obstetrician and gynaecologist at Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun State, Dr. Olusoji Jagun, says usually, pregnant women are not expected to sleep on their back, especially in their third trimester.
He explains, "When you lie on your back, the weight of the pregnant uterus slows the return of blood to your heart, which reduces blood flow to the foetus. That means the baby is getting less oxygen and fewer nutrients."
So, the recommended sleeping position for a pregnant woman, experts say, is sleeping on the left side.
Family doctor, Akin Bajulaiye, says sleeping on your left side is very beneficial for the baby in the womb. He says, "It may benefit your baby by improving blood flow and, by implication, nutrients, to the placenta. It also helps the pregnant mom's kidneys to efficiently eliminate waste products and fluids from the body. This confers the advantage of reducing the probability of swelling in the ankles, feet, and hands."
For infants under one year of age, experts warn against placing a child to sleep in "prone position."
"By 'prone position,' we mean putting a child to sleep on his stomach," explains paediatrician, Dr. Abimbola Ogunnusi.
Ogunnusi notes that though Sudden Infant Death Syndrome - an unexpected, sudden death of an infant under one year of age -remains unexplained even after an autopsy and thorough medical investigation, "researches suggest that an infant who sleeps on his or her stomach and whose head becomes covered by bedspreads may begin to overheat. And though the brain usually triggers the infant to wake up and move to free his or her head, the overheating may inhibit the brain's protective wake-up signal, resulting in SIDS."
She says that's why global authorities such as the National Institutes of Health and the American Academy of Paediatrics advise parents to place babies on their backs to sleep.
"This is called back-to-sleep, and it has been known to reduce cases of SIDS by over 50 per cent," Ogunnusi counsels.
Spine, neck health
For the rest of the population, scientists say the best way to sleep in order to maintain spine health is to sleep on the back, with the arms secured by the sides. "This is good for the spine and the neck," scientists say.
Again, this position, it is said, prevents facial wrinkles "because nothing is pushing against your face." The only downside here, they warn, is that the sleep position may make you snore more than you are wont to if you took less stringent position.
If you are looking for a way of improving digestion, experts say, you can sleep on your stomach (face down). The only issue you may have to contend with, they warn, is that it can put an enormous strain on the neck, as you may have to face one particular direction.
Author of Sleep Interrupted/clinical assistant professor of otolaryngology at New York Medical College in Valhalla, Steven Park, advises that side sleeping is also advantageous "because it helps keep your airways open."
There are pros and cons to this, though. "Research suggests that sleeping on the left side can relieve heartburn symptoms, while right-side sleeping makes them worse," Park counsels.
Experts also note that sleeping on the left side can put strain on internal organs like the liver, lungs, and stomach, even when it minimises acid reflux.
And if you are wondering why you sometimes wake up with back and neck pain, even after you had slept soundly, experts say it may be because you sleep curled up into a ball, with the knees drawn up and your chin tilted down. Called the foetal position, physicians say it can restrict deep breathing.
Use good mattress
In conclusion, experts note that it is absolutely impossible to maintain a particular sleep position throughout the night, but that in order to enjoy good quality sleep, you should mind the condition of your mattress.
"This will often dictate your sleep position. If you have an old, worn-out mattress that sags in the middle, sleeping may become a nightmare," they conclude.