The Pros and Cons of Caffeine

In honor of Caffeine Awareness Month, House Call Doctor sets the record straight on caffeine. Get the facts on the benefits and potential hazards of your morning cup of coffee.

Sanaz Majd, MD
5-minute read
Episode #182

March is Caffeine Awareness Month so I thought it would be the perfect time to discuss caffeine - arguably the most easily accessible and widely consumed drug in the world. 

Many of us fall into one of two camps - we are either coffee drinkers or tea drinkers.  And then there are those in between who feed the billion-dollar soda and energy drink industry. 

See also: Does Caffeine Block Iron Absorption?


Perhaps because of this widespread caffeine consumption, more controversy and myths seem to surround this stimulant than any other.  One day we discover that it’s the fountain of youth and the answer to longevity, and the next day we're told that one more drop can send us to our grave.

What to believe?

Well, in spite of all you may have heard, to this day there is no definitive consensus within the medical community on whether or not we should recommend caffeine.  Let's first find out exactly why this is so and then tackle what we do know about caffeine so far.

Understanding Caffeine Studies

Most medical guidelines and recommendations are based on research studies. Which means that respectable physicians should not simply tell you that the solution to your lifelong battle with weight loss is to consume acai berries (sorry, Dr. Oz). Doctors can't just claim anything under the sun and shouldn’t make health-related recommendations without valid research to back them up. 

Almost anyone can organize a study to show that acai berries are the miracle answer to our fat burning dreams.  However, there are good studies and not-so-good studies.  Well-respected studies in medicine, hence the term "evidence-based," often include specific features that doctors look for to give them validity.  Examples of these key features include:

  • the study includes a large number of subjects

  • the study has a “control” group (that's been given a placebo)

  • the study is “double-blind” (which means even the researchers don't know which subjects receive the compound in question and which receive the placebo)

  • the study is free from confounding factors (a term we call “bias”)

Please keep these in mind as you examine any future medical studies that happen to cross your Google medical searches, whether they concern acai berries, the supposed risks of the Measles Mumps and Rubella (MMR) vaccine, or caffeine.

Most studies of caffeine are in the category of “observational studies,” that means that a group of people who consume caffeine are observed through time.  So there is no “control” group and no one here is “blind” as to who is drinking caffeine and who isn’t.  Therefore, there tends to be some bias, which makes the studies less than ideal. 

What we do know for sure is that caffeine affects multiple organ systems in various ways – the brain, heart, gastrointestinal system, and even metabolism.  Let’s discuss what the latest research tells us about the pros and cons of caffeine.

What Are the Pros and Cons of Caffeine?

More than 150 million people in the U.S. are daily caffeine consumers, with most being coffee drinkers. Other common sources of caffeine include tea, soda, chocolate, energy drinks, and dietary supplements all with variable concentrations of caffeine. The concensus in the medical community is that consuming up to 400 mg of caffeine per day (that's roughly about 3 cups of coffee), has been found to be pretty much harmless. This is what doctors refer to when they talk about drinking coffee "in moderation."

Here is a summary of the results of caffeine studies:

The Pros of Caffeine*

*Please note that most of these benefits pertain to caffeine consumed in moderation (400 mg per day), not in excess.

  • Caffeine can improve attention and focusing abilities, especially in sleep-deprived workers or those experiencing jet lag.  This is precisely the reason why so many people consume caffeine in the first place, why many adults with ADHD tend to self-medicate with caffeine, and perhaps why it’s often used first thing in the morning.

  • Caffeine can mildly enhance athletic performance. Check out Get-Fit Guy's episode Can Caffeine Help You Work Out? for more details on how to use caffeine to boost your workouts.

  • Caffeine can decrease the risk of developing Parkinson’s disease. The only exception is for postmenopausal women on hormone replacement therapy, where it tends to do the opposite.

  • Caffeine may protect against the development of Alzheimer's disease

  • Caffeine may protect against cardiovascular events, like heart attacks.

  • Caffeine decreases the risk of developing diabetes and may even help to decrease insulin resistance in diabetics who consume it regularly.

  • Caffeine can aid in constipation.

  • Caffeine may be liver-protective – studies show some protection against possible alcoholic cirrhosis and Hepatitis C progression.

  • Caffeine may be protective against gout - an acute, severely painful inflammatory condition of a joint (commonly the  big toe).

  • Consuming 2-3 cups of caffeine a day has also been shown to decrease the risk of overall death due to any reason, what doctors and scientists refer to as “all-cause mortality.”


Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.

About the Author

Sanaz Majd, MD

Dr. Sanaz Majd is a board-certified Family Medicine physician who graduated from Drexel University College of Medicine in Philadelphia. Her special interests are women's health and patient education.