Fact vs Myth about Caffeine

Written by UConn Dietetics Masters student Casey Henderson

Caffeine. From regular coffee drinkers who are convinced they need that first cup before anyone can speak to them, to college students who claim the caffeine keeps them awake to study for a big test, we all consume caffeine in different ways. How does caffeine really work? How can we monitor it and still enjoy our daily intake safely?

Caffeine is a naturally occurring substance found in certain plants. It has also been adapted to a manmade form as an additive.1 We can find it in a multitude of products, particularly in beverages, such as coffee, tea, energy drinks, pre-workout beverages, sodas, and some juices. It can also be consumed in pill form as a supplement. Caffeine is absorbed quickly by the bloodstream and delivered to the brain to produce a feeling of alertness as a short-term solution to feelings of drowsiness.1 There is no nutritional value to caffeine and therefore it is not necessary in the diet for any reason.1 The Food and Drug Administration (FDA) lists the current upper limit on caffeine at 400 milligrams per day.2

How much caffeine do we get in our beverages every day?

Approximate caffeine content of typical drinks:

  • Classic drip coffee, 75-100 mg per 6-ounce cup1
  • Espresso, 40 mg per 1 oz (single shot)1
  • Black tea, 60-100 mg per 16 oz1
  • Cola, 60 mg per 12oz can1
  • Energy drinks, 60-300mg per 16oz can2

Most drinks are well within the moderate and safe caffeine limit when consumed by adults. However, caffeine can affect people differently and each person will have different limits on how much they consume for the effects they receive.2  This difference is based on a person’s ability to metabolize caffeine and explains why you may be able to consume a 16oz coffee and feel ready to take on the day, but your coworker has an 8oz coffee and they are fidgety and distracted.2 Side effects of caffeine over-consumption can include insomnia (inability to fall asleep or waking up and not being able to fall back asleep); jitters; anxiousness; increased heart rate; upset stomach; nausea; and headache.2 It’s a good idea to monitor your daily caffeine intake, and if kids are in your life, monitor what beverages– potentially with large amounts of caffeine– they may be drinking, too. Currently, there are no US federal guidelines for caffeine intake for children. The American Academy of Pediatrics discourages caffeine consumption for kids.3

 Common myths about caffeine

  • A person who is pregnant cannot consume caffeine: False, a person who is pregnant can still consume moderate amounts of caffeine limiting it to about 200 mg per day.2
  • Caffeine can help move alcohol out of the system more quickly: False. Although caffeine is a stimulant to the nervous system, it cannot replace the lost coordination and decision-making skills depleted by alcohol.2


  1. https://medlineplus.gov/ency/article/002445.htm
  2. https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much#:~:text=4.,associated%20with%20dangerous%2C%20negative%20effects
  3. https://downloads.aap.org/dochw/dshp/Healthy%20Beverage%20Quick%20Reference%20Guide_Updated_9.1.23.pdf


This material is funded by USDA’s Supplemental Nutrition Assistance Program (SNAP).

This institution is an equal opportunity provider.