In January 2019 researchers from the USA published their review of the medical scientific literature on caffeine intake in children and adolescents. Caffeine is the most widely consumed stimulant in the world, and in children and adolescents intake can be from soda, tea and coffee, and energy drinks. In addition, the availability of highly caffeinated beverages and foods has been increasing over the past decade, some of which are marketed directly to children and adolescents. According to recent data from the National Health and Nutrition Examination Survey, over 75% of children (aged 6-11 years) and adolescents (aged 12–17 years) consumed caffeine regularly. Children had an average daily consumption of 25 mg/day, the main source of caffeine being soda (40 mg/12 oz), followed by coffee (100 mg/8 oz) and tea (48 mg/8 oz). In adolescence, the average caffeine consumption increased from about 50 mg/day to 180 mg/day. This was generally due to an increased intake of soda and coffee, although in some adolescents and young adults it appeared to be from additional tea consumption and energy drinks. Excessive intake of caffeine among adolescents and young adults has been associated with an increased tendency for risk taking, increased alcohol consumption, increased cigarette smoking, illicit drug use and high-risk sexual behaviour. In fact, the American Academy of Pediatrics recommends that children limit their caffeine consumption and abstain completely from the consumption of energy drinks.
The caffeine intake from energy drink consumption in children and adolescents has caused great concern, especially as there have been deaths amongst teenagers linked to excess energy drink consumption. There are many ingredients in energy drinks which are either unknown or classified as “proprietary herbal blends”. These include caffeine-containing additives such as taurine (a naturally occurring organic acid often used as a nutritional supplement), guarana (a plant with seeds that are high in caffeine) and green tea extract. Another ingredient frequently found in energy drinks is ginseng which intensifies the effect of caffeine. A second risk of energy drinks and energy shots is that they contain a relatively large amount of caffeine per serving (from 80 to over 250 mg). This is the equivalent of 1 to 3 cups of coffee. Energy drinks are frequently marketed as mixers for alcoholic beverages, and those who consume energy drinks generally report a higher alcohol intake than those who do not.
In their review, the researchers included a total of 90 articles plus 10 additional sources of information which came from websites, workshop proceedings and newspaper articles.
Results of the review showed that the majority of medical scientific literature has concluded that moderate caffeine consumption in children and adolescents is relatively safe. In fact, caffeine consumption has been shown to produce enhanced feelings of well-being, improved concentration, increased arousal and energy. However, higher doses of caffeine have been linked to physiological, psychological, and behavioural problems, particularly in children with mental health or cardiac conditions. It is known that in adults, high doses of caffeine (over 400 mg) can lead to increased anxiety, nausea, jitteriness, and nervousness. In children, these same effects can also be observed – but at lower doses (approximately 100–400 mg).
When caffeine is consumed late on in the day it can take longer to fall asleep, impair sleep quality, and reduce sleep duration. This in turn can lead to feelings of fatigue upon waking, and consumption of caffeine to stimulate wakefulness. Caffeine is also known to increase the frequency of sleep disruption which in adolescence can be especially bad as this is a time of rapid growth that requires adequate sleep. Sleep disruption can also affect academic performance, which is why paediatricians generally recommend that caffeine intake is limited in children and adolescents and avoided within a few hours of bedtime.
High caffeine doses of over 400 mg are associated with caffeine intoxication, which can result in tachycardia, increased blood pressure and cardiac arrhythmias. Some cardiac conditions can also be made worse by high doses of caffeine. This is especially true in hypertrophic cardiomyopathy, which is the most common genetic cardiomyopathy in children. When a child is diagnosed with a cardiac condition, doctors should inform parents that caffeine consumption could potentially make their child’s symptoms worse.
A high caffeine consumption (3−9 mg/kg/day body weight) has been seen to increase the occurrence of headache, stomach ache, gastroesophageal reflux and nausea in children. To put this in context, the average weight of 5-12-year-olds tends to range from 20-40 kg. Calculated from an average weight of 30 kg, 3-9 mg/kg would be 90-270 mg of caffeine, which is equivalent to 2 cans of soda or 3 cups of coffee. Although children are unlikely to consume the high end of this range, the consumption of 2 cans of soda is not unusual in children.
There is increasing evidence that caffeine consumption is associated with social, emotional, and behavioural problems. When children regularly consume caffeine and then stop, their concentration can decrease and at the same time increases the time it takes for them to react. Some studies have suggested an association between caffeine consumption and longer-term behavioural problems in youth, such as anger, violence, and alcohol and drug use. In older adolescents and young adults, the association between energy drinks and risk-taking behaviour, such as illicit drug use, risky sexual behaviour, participation in extreme sports, and physical violence, appear to be even stronger. In addition, energy drinks have also been associated with shorter sleep duration, a greater degree of interrupted sleep and reduced sleep quality.
Caffeine added to beverages may also promote unhealthy food and beverage intake. Studies have shown that caffeine intake by children and adolescents appears to increase their liking for certain sugar-sweetened beverages. In addition to increasing certain preferences, studies have also shown that caffeine added to sugar sweetened beverages can make the child and adolescent want to consume more of these beverages. This type of conditioning has been seen to occur with the consumption of tea, soda, and coffee-type drinks, which suggests that caffeine may promote liking and intake of a variety of beverages, including those that do not normally contain caffeine. This could result in an increased consumption of caffeine-containing beverages amongst children and adolescents, perhaps at the expense of healthier beverages, such as water or milk.
Caffeine consumption can interact with a variety of mental health conditions in children and adolescents, and also with the medications commonly used to treat these conditions. Increased caffeine intake from energy drinks has been shown to be associated with conduct disorders, whilst a higher coffee consumption increases the risk of panic and anxiety disorders. Whilst some studies have been able to reproduce the association between caffeine and anxiety, especially amongst males, other studies have shown no association. Caffeine intake also appears to be associated with an increased risk of depression in children, particularly in girls.
In contrast, however, caffeine appears to be beneficial for some of the symptoms observed in medical conditions, such as attention deficit-hyperactivity disorder, as caffeine consumption can increase concentration. In fact, some parents have reported using caffeine as a way of managing some of the symptoms seen in attention deficit-hyperactivity disorder.
It is recommended that caffeine consumption should be included in conversations between psychiatrists and their paediatric patients so it can be assessed whether caffeine could be making symptoms worse or even interacting with medications. It should also be noted that caffeine intake can disrupt sleep, and sufficient sleep is important for many aspects of mental well-being as seen in medical conditions such as depression, anxiety, and emotion regulation.
The researcher concluded by recommending that healthcare professionals should incorporate better educational and counselling strategies on the potential harm of excessive caffeine consumption into their standard care and that government agencies should develop programmes to inform consumers, especially children and adolescents, about the dangers of products with a high caffeine content.
Temple JL. Review: Trends, Safety, and Recommendations for Caffeine Use in Children and Adolescents. J Am Acad Child Adolesc Psychiatry. 2019 Jan;58(1):36-45.