Caffeine and Kids: An Update for Parents

What parents should know about the effects of caffeine on children and teens

Posted Dec 27, 2018

With so much deserved attention being paid to vaping, cannabis, and opiates, it is easy to forget about one of the most widely used substances in childhood and adolescence – caffeine.  Fortunately, a new review paper published in the Journal of the American Academy of Child & Adolescent Psychiatry helps bring us up to date with what is known and isn’t known about the effects of caffeine consumption on youth, based upon 90 different individual studies.

Rates of Caffeine Use

About 75% of older children and adolescents consume caffeine regularly, often at an average dose of about 25mg/day for children between the ages of 6 to 11 and 50mg/day for adolescents. The paper helps convert those dosages into some common products:

  • Soda (12oz) about 40mg
  • Coffee (8oz) about 100mg
  • Tea (8oz) about 48mg
  • Energy Drinks (12oz) about 150mg plus with 5-Hour Energy being around 215mg according to a Consumer Reports study

Pay attention to the serving sizes, as the actual amount in a purchased beverage is often much more (I’m not sure you can even get an 8oz coffee at Dunkin Donuts, for example).  Somewhat surprising to me, total caffeine consumption among youth over the past decade or so looks relatively flat and may even be decreasing despite the fact that energy drink sales are rising and being marketed to kids. This fits with what we know about substance use in general, with the rates dropping for our current generation of adolescents for most everything, with the notable exception of cannabis.

Effects of Caffeine

Caffeine is a stimulant and can increase arousal, alertness, and amount of motor behavior.  There are some studies that show improvements on some cognitive tests when children take moderate doses of caffeine, but these effects tend to be most pronounced for kids who don’t consume much caffeine at baseline.  At the risk of stating the obvious, one of the most consistent effects of caffeine is that it can reduce feelings of fatigue and sleepiness.  Many parents of children who meet criteria for ADHD also report some benefit, although more systematic data on this subject is lacking.

There also, of course, are some downsides.  One of the big ones is that caffeine can interfere with sleep, inducing a cycle that reinforces more caffeine use in the day to compensate for the poor sleep at night.  A less obvious negative effect may be that caffeine added to sweet beverages can increase consumption of other sugary foods, even if they don’t have caffeine.

At higher doses (which may be in the level above 400mg/day for teens and just about 100mg/day for younger kids), the risks rise for of a number of other negative effects, such as heart arrhythmias, agitation and irritability, blood pressure increases, and anxiety. There have even been a number of cases of sudden death that have been attributed to high caffeine intake, although overall this is rare.  One complicating factor that might increase the risk of a serious medical event with caffeine is having an underlying cardiac problem, which unfortunately often goes undetected until the event happens. Referring back to the conversions above, some parents might be a little surprised to see how easily a child can get to a dose of caffeine that is considered excessive.

There are also a few large long-term studies that have shown an association between increased caffeine consumption and future problems with anger, aggression, risky sexual behavior, and substance use.  Energy drinks, which can deliver a lot of caffeine quickly, were singled out as particularly problematic in some of these studies, although determining causation in these kinds of studies is always tricky. It may be that teens who are already prone to have these kinds of behavioral problems already are the ones who also likely to seek out high volumes of caffeine. On the other hand, the review also mentions animal studies that indicate that caffeine may prime the brain to use other substances like amphetamines or cocaine. Energy drinks also often contain other substances with similar effects that are relatively untested. 


All told, the FDA considers caffeine as generally safe at low doses, and there does not appear to be much evidence that low or moderate use in youth leads to significant problems.  The story changes, however, with higher levels of consumption, and the article recommends that both parents and doctors be more vigilant in monitoring caffeine intake in youth (and the time of day it is being used) and in limiting intake to smaller amounts.  The article also urges more research especially in youth, as many of the regulations and standards regarding caffeine use are old and developed from adult data.

Caffeine is not heroin, and it would be alarmist and personally hypocritical of me, as someone who loves a good cup of coffee or two in the morning, to conclude that the data broadly implicates caffeine as a major public health problem. At the same time, this review highlights the fact that caffeine can cause some real problems in children and teens, especially in higher amounts, and shouldn’t be given a total pass by parents and doctors alike.


Temple JL. Review: Trends, Safety, and Recommendations for Caffeine Use in Children and Adolescents. Journal of the American Academy of Child & Adolescent Psychiatry 2019; 58(1):36-45.