The Truth About Caffeine and Your Brain

Whether it’s cramming for finals, preparing for that presentation to your new boss, or trying to make up for a month’s worth of missed exercise in one afternoon at the gym – we’ve all been there, having that 2nd or 3rd or (gasp!) 4th cup of coffee to fuel a 16 hour day.  Hopefully, it’s an occasional splurge, and our daily routine doesn’t depend on an excess of caffeine.  But if it does, if we’re regularly running on a few lattes are there repercussions besides a high Starbucks tab?

Philosophies on this vary.  We’ve all heard the general guidelines to keep daily limits to 2 or 3 cups.  But how much are we actually drinking?  According to the FDA, 90% of people worldwide use caffeine in some form and 80 percent of U.S. adults consume caffeine each day, with an average intake of about 200 mg, or two five-ounce cups of coffee.

Other estimates put the average American coffee drinker at closer to 300 mg.  According to the Mayo Clinic it is generally agreed that the definition of moderate caffeine consumption is between 200-300 mg. Daily doses higher than 500 to 600 mg daily are considered “heavy users.”   And surprisingly according to a recent BBC report the US does not rank among the highest in caffeine use worldwide, in fact, Finland ranks #1 with the average adult usage topping off at 400 mg.

So if 80-90% of us are using some form of caffeine daily – are there any short or long term health effects to be mindful of?  It depends mostly on your usage.  According to the Mayo Clinic, heavy users (500 to 600 mg a day) may experience these side effects:

  • Insomnia
  • Nervousness, restlessness or irritability
  • Stomach upset
  • Fast heartbeat
  • Muscle tremors

If you don’t drink caffeine often you will probably be more susceptible to side effects, as a tolerance will build up over time.  Other factors that affect how your system processes caffeine include body mass, age, certain medications or herbal supplements and health conditions like anxiety disorders. Research also indicates that men may be more susceptible to the effects of caffeine than women.

For the most part, the negative effects of moderate caffeine use seem to be transitory.  The Mayo Clinic reports that recent studies have generally found no connection between coffee and an increased risk of cancer or heart disease but actually a decreased overall mortality and cardiovascular mortality.  Additional studies also credit coffee with health benefits, including protecting against Parkinson’s disease, type 2 diabetes and liver disease. Caffeine also appears to improve cognitive function and decrease the risk of depression.

But there are risks besides transient symptoms to keep in mind. Heavy use of unfiltered coffee (boiled or espresso) has been associated with mild elevations in cholesterol levels. And an increased risk of heart disease has been found in people with a specific (and common) genetic mutation that slows the breakdown of caffeine. Overall, how quickly your body can metabolize caffeine may affect your health risk.  And don’t forget the calories!  Fancy coffee drinks can pack a huge calorie punch – with flavored whipped-cream topped lattes delivering a whopping 500+ calories.

With caffeine, follow the “all things in moderation” adage and you’ll do your health and pocket book a favor.


  1. Dr.Michael Sturgis on June 17, 2015 at 4:54 am

    Excellent article. I am working with several individuals in which there maybe dependency issues regarding caffeine.

  2. Linda K on July 13, 2015 at 3:46 am

    Thanks for pointing out the “size” factor. Since I usually drink only one cup of coffee a day, I thought that was well within the low caffeine range. However, my one cup is 16 oz., which is more than three times the normal 5 oz. cup! Time to rethink.