SINGAPORE - Controlling children's access to electronic devices is key to ensuring they get quality sleep, which is important for their physical and intellectual development, said experts.
Paediatric specialists told The Sunday Times that children who get insufficient sleep are also at higher risk of developing a sedentary lifestyle that can lead to obesity, which can then lead to other health problems when they are older. These include heart disease, high blood pressure and other chronic illnesses.
That is why, they said, it is important to make sure screen time for children is tightly regulated, and parents practise good sleep hygiene, which refers to a bedtime routine and environment that are conducive to sleep.
The issue of children's sleep is in the spotlight again after Sengkang GRC MP Jamus Lim from the Workers' Party and Tampines GRC MP Cheng Li Hui from the People's Action Party asked in Parliament last Tuesday if there were plans to re-evaluate school start times.
In response, Minister of State for Education Sun Xueling said schools have the autonomy to start later, based on factors like parents' feedback. She also said it is key that parents try to improve their children's sleep hygiene and manage their use of devices, among other things.
In response to queries from The Sunday Times, Associate Professor Teoh Oon Hoe, who is the head and senior consultant of respiratory medicine service at KK Women's and Children's Hospital's (KKH) department of paediatrics, said the use of electronic devices before bed can be stimulating to the brain.
"Blue light from the screens of digital devices suppresses the production of sleep-promoting melatonin from the brain's pineal gland. This makes it difficult for children to fall asleep," he said.
Dr Michael Lim, senior consultant from the pulmonary medicine and sleep division in the department of paediatrics at the Khoo Teck Puat - National University Children's Medical Institute at National University Hospital, agreed.
He said the prevalent use of electronic devices before bedtime is an issue here. "Social media interactions, messaging apps and video games compound the problem by increasing mental, emotional and physiologic arousal, all of which disrupt sleep."
A study done by Dr Lim and his team found that during home-based learning, which was implemented during the circuit breaker last year to curb the spread of Covid-19, children slept more.
But what is the right amount of sleep for children?
Dr Amy Wang, specialist in paediatric medicine and consultant at Raffles Children's Centre, said primary school children should have nine to 11 hours of sleep, while teens need between eight and 10 hours of sleep daily.
At puberty, there is a shift in an adolescent's internal clock by about two hours, she said.
"This means a 14-year-old, who used to fall asleep easily at 9pm, will have difficulty falling asleep before 11pm. At the same time, his natural waking time also shifts to two hours later. This makes it very difficult for him to get up early, before 7am or 8am."
Dr Lim said it is important to get enough sleep the night before and the night after learning, because sleep restores the brain's capacity for learning and makes room for new memories.
Studies have shown that sleep deprivation can have adverse effects on a child's health.
Dr Wang said children may have problems with memory, attention and concentration, which can affect their academic performance.
"There is also evidence that long-term sleep deprivation is associated with a weaker immune system, obesity, cardiovascular disease, and diabetes," she said.
Dr Cheng Zai Ru, from KKH's respiratory medicine service, said that sleep-deprived children can have trouble controlling their emotions and may display behaviours like aggression and tantrums, and show signs of anxiety and depression.
That is why it is important to establish a regular schedule to ensure children have enough sleep.
Dr Wang said children should avoid screen time at least one hour before bedtime, and parents should lead by example.
Dr Lim advised parents not to allow children to use electronic devices excessively during the day and to keep all electronic devices outside the bedroom at bedtime.
He said: "The short-term effects of sleep deprivation can be reversed once the child starts getting adequate good-quality sleep as a matter of routine."