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Is caffeine good for me or bad for me?



80-135mg 2 tablets of aspirin or acetaminophen + caffeine
80-125mg 1 cup coffee
80mg Red Bull
40-60mg tea
35mg cola
20mg dark chocolate (1 oz)
15mg cocoa
2-4cups decaf coffee

Caffeine is good, and it’s bad – it’s complicated. Allow me to explain. First, above are the numbers, comparing milligrams of caffeine in various substances.

Now, the evidence. You already know that caffeine tends to make people more alert. Caffeine in even low to moderate amounts (30-350 mg) improves alertness, concentration, learning, and decision-making (1). It’s helpful to people whose circadian rhythm has been disrupted, such as with jet lag and shift work (2).

For the most part, caffeine has no serious long-term health effects. In fact, coffee consumption is associated with decreased overall mortality (3). But now, it gets more complex:

Sleep: Friend or Foe?

Since caffeine increases alertness and mitigates the effects of sleep deprivation (4), the other side of that coin is that caffeine makes it take longer for you to fall asleep, stay asleep, and have deep sleep (5). Caffeine ingested within six hours of bedtime more than doubles the time it takes to fall asleep.

Headaches: Cause or Cure?

Headaches and caffeine have a complicated relationship. Kind of a love-hate thing. On the one hand, caffeine can alleviate both routine (tension) and migraine headaches. Analgesics that contain caffeine are more effective against headaches than analgesics alone (6). However, habitual consumption of caffeine is associated with both chronic migraines and analgesic rebound headaches (the phenomenon where you get a headache from taking analgesics too often) (7). What is more, when people consume more than 750 mg of caffeine a day, the pain-relieving effectiveness of the caffeine may diminish.

Dr. J’s Recommendations:

Don’t drink coffee or consume other forms of caffeine within six hours of going to bed.

Don’t overdo pain medications containing caffeine. In fact, if you have chronic tension or migraine headaches, try to gradually wean yourself off of caffeine altogether. After you do that successfully, when you do get a headache, having some caffeine will deliver a much bigger pain-killing bolt.

And of course, if your headaches keep getting worse, please see a doctor. I mean it!

  • 1.Smith A et al. Effects of repeated doses of caffeine on mood and performance of alert and fatigued volunteers. J Psychopharmacol. 2005;19(6):620.

  • 2.Ker K et al. Caffeine for the prevention of injuries and errors in shift workers. Cochrane Database Syst Rev. 2010.

  • 3.Crippa A et al. Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis. Am J Epidemiol. 2014 Oct;180(8):763.

  • 4.Lieberman HR et al. Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land. Psychopharm 2002; 164(3):250.

  • 5.Clark I, Landolt HP. Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials. Sleep Med Rev 2017; 31:70.

  • 6.Goldstein J et al. Acetaminophen, aspirin, and caffeine in combination versus ibuprofen for acute migraine: results from a multicenter, double-blind, randomized, parallel-group, single-dose, placebo-controlled study. Headache. 2006;46(3):444.

  • 7.Bigal ME et al. Chronic daily headache: identification of factors associated with induction and transformation. Headache. 2002;42(7):575.

  • 8.Fennelly M et al. Is caffeine withdrawal the mechanism of postoperative headache? Anesth Analg 1991; 72(4):449.