Parents, doctors and researchers have fretted about whether or not children get enough sleep since at least the turn of the last century, producing studies and tracking data about the health consequences of drowsiness.
Sleep is essential to brain plasticity, building neural connections and memory, and to preventing diseases like diabetes and heart disease. Recently, scientists connected chronic sleep curtailment and inconsistent bedtimes to obesity, impaired cognitive functioning and ADHD symptoms.
According to a review of studies from 20 different countries dating back to 1905, children today sleep an average of 1 hour and 25 minutes less than they did 100 years ago. The trend shows no sign of improving.
The National Sleep Foundation estimates that 30 – 60 minutes of the overall sleep decline has occurred within the past 20 years.
Chronic Sleep Curtailment Connected to Childhood Obesity
For infants and children under the age of 2, the National Sleep Foundation recommends at least 12 hours of sleep per day; for ages 3-4, 10 hours; and from ages 5-7, 9 hours. The foundation defines anything less than this amount as “sleep curtailment.”
To study the long-term effects of sleep curtailment in early childhood, Dr. Elsie Taveras and her colleagues at Masschusetts General Hospital recruited pregnant women in eastern Massachusetts. The doctors tracked sleep and health measures for both the mothers and children (1046 of them) until the children reached the age of 7.
The researchers asked mothers to record their children’s sleep duration during a regular 24-hour weekday and a weekend day, including naps when applicable.
The research showed association between less sleep at any point in early childhood with higher body mass scores at age 7. Furthermore, BMI scores decreased incrementally with each additional increase in the amount of sleep. However, children who got less sleep typically came from lower income households with less educated mothers and spent more time watching TV.
While the authors ruled out TV time as a cause for obesity, the same household routines that lead to outsized television viewing may also contribute to a child’s lack of sleep. In other words, while lack of sleep correlates with obesity, it is possible that another factor is the cause of both issues.
Drowsiness Mimics ADHD Symptoms
Children rarely admit that they are sleepy and do not exhibit the same signs of sleep deprivation as adults. In fact, many of the signs of sleep deprivation in children mimic those of ADHD. Children often become hyperactive and over-emotional and have difficulty concentrating on tasks.
Karen Bonuck and her colleagues studied data from over 13,000 British children, tracking them from birth to age 7. Children who suffered sleep disruptions such as breathing problems (snoring or sleep apnea, for example) scored lower on behavioral and emotional scales and were more likely to be hyperactive at ages 4 and 7.
Furthermore, even children whose sleep patterns returned to normal after age 2 ½ still showed problems at age 7. The authors surmise that this may be because children have experienced disruption at a critical time in brain development.
The researchers determined that sleep disordered breathing accounted for more ADHD-like behaviors than any pre-natal issues, including maternal alcohol use and smoking. However, poverty, a disorganized home environment, and simply being male were better predictors than sleep disruption of hyperactivity at age 7.
Medical conditions, like enlarged tonsils or obesity, may cause some breathing problems during sleep. However, some of the same poverty and lack of household routine issues connected to hyperactivity – and even some drugs used to treat ADHD – can cause a similar disruption of sleep.
Inconsistent Bedtimes Associated with Poor Concentration
According to data collected by the UK Millennium Project, is it not lack of sleep, but inconsistent bedtimes that cause problems for children. Children with irregular or late (past 9:00 pm) bedtimes at age 3 scored significantly lower on reading and spatial tests at age 7.
However, as with the children in the obesity and ADHD studies, children with irregular bedtimes were also more likely to live in poverty and have parents with lower education levels. Inconsistent bedtimes were also associated with what the authors referred to as “unfavourable routines,” like skipping breakfast, having a TV in the bedroom, and not being read to daily.
When researchers included these confounding factors in the mix, bedtime routines still remained an immediate significant factor in limiting cognitive functioning for girls, but the effect on boys disappeared. However, the cumulative effects of inconsistent bedtimes throughout early childhood remained connected to lower scores in reading, math, and spatial abilities.
Should Parents Worry About Children’s Sleep?
While all of the studies found strong correlations between disrupted or irregular sleep and physical, cognitive and emotional function, none proved direct causation. However, causation is often difficult to prove in studies concerning children as no parent wants to consciously deprive their children of sleep just for the sake of research.
The bottom line, according to the researchers, is that parents should talk to their pediatricians about how much sleep their children get, the quality of that sleep, and how much sleep children need.© Copyright 2015 Nicole Fravel, All rights Reserved. Written For: Decoded Parenting