Is Coffee Helpful or Harmful?

is coffee helpful or harmful

Is Coffee Helpful or Harmful?

Video | Anxiety | Sleep | Addictive | Blood Pressure | Heartburn | Diuretic | How Much | Antioxidants | Heart Health | Live Longer | Diabetes | Weight Loss | Autophagy | Mental Alertness (Alzheimer’s)

Nearly two-thirds of us enjoy a morning cup of coffee and its popularity has been climbing every year (1)(2).

Is drinking coffee OK or are we doing our bodies harm by drinking cup after cup, day after day? In this post, I’ll share the good and bad of coffee. We’ll investigate how it impacts your health and weight. 

Is Coffee Okay to Consume? – Summary

  • The Harmful Side Effects of Coffee – Consuming too much coffee can lead to harmful side effects like anxiety, trouble falling asleep, dependency, heartburn, and increased blood pressure.
  • Is Coffee a Diuretic? – A new coffee drinker will notice an increase in bathroom visits, but they will quickly develop a tolerance to this effect. Coffee will not dehydrate regular coffee drinkers.
  • How Much Coffee Is Too Much? – According to research, consuming up to 400 milligrams of caffeine a day, about 32oz, was not associated with overt, adverse effects.
  • The Helpful Benefits of Coffee – Studies show coffee can help you live longer, reduce your risk of diabetes, support fat loss, enhance autophagy, and reduce your risk of Alzheimer’s and Dementia while providing you short-term mental clarity.

Is Coffee Helpful or Harmful? [Video]

In this video, you’ll learn…

  • Studies about the various ways coffee affects our bodies.
  • The positive and negative symptoms of coffee.
  • Health conditions that may require you to be careful with caffeine.

Coffee May Lead to Anxiety

For many of us, the mere thought of giving up coffee fills us with anxiety. But is that anxious feeling coming from the coffee itself?

Well, there is scientific evidence that consuming too much caffeine, especially in sensitive individuals, can leave you feeling jittery and may worsen feelings of anxiety (3) (4).

Coffee May Interfere with Sleep

Coffee can also interfere with your ability to sleep soundly if you drink it too close to bedtime. The half-life of caffeine is about six hours.

This means that six hours after you drink a cup of coffee, half of the caffeine from that cup is still in your system.

It is a stimulant, so if you are drinking caffeinated coffee long into the afternoon, it will impact your ability to sleep later that night.  

coffee and interrupted sleep

Caffeine is Addictive

Caffeine is also addictive. If you stop drinking it, you will likely suffer withdrawal symptoms including headaches, irritability, and brain fog.

As anyone who has experienced caffeine withdrawal knows, these symptoms are unpleasant, but there is no evidence that the symptoms themselves present a health concern. They typically subside on their own within a day or two.

Coffee and Your Blood Pressure

If you have high blood pressure, you may want to consider reducing your caffeine intake. However, the research into the link between caffeine and higher blood pressure is not particularly strong.

While there are studies that showed increased blood pressure with caffeine consumption, the increase was slight (5)(6)(7).

Coffee and Heartburn

Heartburn, while not associated with the heart itself, is a problem for some people.

There is clinical and anecdotal evidence that shows that reducing caffeine intake can help alleviate heartburn.

Caffeine relaxes the lower esophageal sphincter, which is the barrier that keeps stomach acid from moving back up toward your throat.

There are many lifestyle factors and physical conditions that contribute to heartburn. While coffee might make the problem worse for some, it might not be the sole culprit (8)(9).

Is Coffee a Diuretic?

Some people worry that coffee is a diuretic that leads to dehydration. However, this contention has been disputed in more recent studies.

A review study that searched the scientific literature related to caffeine and fluid balance found that caffeine will cause you to visit the bathroom more often when you first start drinking it.

But, your body quickly develops a tolerance to this effect, making it a non-issue in those who consume it regularly. They concluded that…

“there would appear to be no clear basis for refraining from caffeine containing drinks in situations where fluid balance might be compromised.” (10)

How Much Coffee is OK?

How much caffeine is safe to consume? A systematic review study conducted in 2017 shed some light on this answer.

They found that consuming up to 400 milligrams of caffeine a day was not associated with overt, adverse effects (11).

To give you an idea of how much coffee that would be, consider that a small eight-ounce cup has about 100 milligrams of caffeine.

up to 400 milligrams of caffeine a day is not harmful

We see that there are some health cautions to consider when it comes to drinking coffee, but there are also health benefits. 

Coffee Contains Beneficial Antioxidants

Coffee comes from the coffee bean and when you brew a cup, many of the beneficial nutrients of the beans are transferred into your cup.

If you drink multiple cups of coffee, you will get multiple doses of these nutrients; many of which act as antioxidants. 

Antioxidants can be thought of as tiny defenders of your cells. When harmful substances try to attack your cells, antioxidants fight back providing a line of defense that lowers your risk of conditions like heart disease and cancer. 

Coffee and Heart Health

Earlier, I talked about blood pressure and caffeine.

While there may be a slight increase in blood pressure due to regular coffee intake, the issue does not seem to translate into an increased risk of stroke or heart disease (12) (13)

Coffee May Help You Live Longer

In fact, being a regular coffee drinking may help you live longer.

A study published in 2012 evaluated the coffee consumption of hundreds of thousands of men and women over the age of 50 and found that “coffee consumption was inversely associated with total and cause-specific mortality.” (14)

Coffee and Diabetes

The positive impact that coffee holds for diabetics may contribute to the longevity benefit.

One of the cornerstones of diabetes is a chronically elevated blood sugar level, which is a problem for your body.

Not only will it encourage high levels of insulin that can block fat loss, but it also creates a state of inflammation that damages your blood vessels.

A systematic review of the scientific literature showed that a “High intakes of coffee, decaffeinated coffee, and tea are associated with reduced risk of diabetes.” (15)

coffee and diabetes risk

Coffee and Weight Loss

Any time that you keep your blood sugar and insulin levels low, you have an easier time releasing fat from storage.

It is not clear if that is part of the mechanism, but we do see that regular coffee consumption supports fat loss. It could be that the nutrients in the coffee combine with the metabolic boost that you get from the caffeine to give you the fat-burning advantage (16).

While coffee might give you an edge when it comes to weight loss, the advantage might not be distributed equally among different demographics.

Some studies showed that the fat liberating advantages of caffeine diminished with age and were less evident in obese individuals when compared to lean subjects (17)(18).

Coffee and Autophagy

Those of you interested in weight loss, may be wondering if coffee is ok to consume when you are intermittent fasting.

Intermittent fasting is the practice of splitting your day between a distinct period of fasting and eating. It is used successfully by many people looking to improve their health and lose weight. 

Even when coffee is consumed outside of your intermittent fasting eating window, it has the potential to increase a process called autophagy

Autophagy literally means “self-eating” and can be thought of as a housekeeping process performed by your cells.

When autophagy is taking place, cells are able to clear out dead or no-longer-needed substances and recycle them for new purposes.

While the research to date has been done on mice, there is hope that the nutrients in coffee enhance autophagy in humans (19)(20).

Coffee and Mental Alertness: Short-Term & Long-Term

Of course, a discussion on coffee would not be complete without mentioning the mental boost that it provides. It seems that this mental clarity advantage might be both short-term and long-term. 

The consumption of coffee has been shown to benefit the brain in ways that lower your risk of dementia and Alzheimer’s disease. And the scientific evidence seems to be strong.

One study stated that “Caffeine intake was associated with a significantly lower risk for AD [Alzheimer’s disease], independently of other possible confounding variables.” (21)

And a systematic review published in 2016 showed that “higher coffee consumption is associated with reduced risk for Alzheimer’s disease.” (22)

coffee and Alzheimer's Disease

The Bottom Line on Coffee

The bottom line on coffee is that it has health benefits that may aid you in living longer, being healthier, and controlling your weight.

But, if you are prone to anxiety, high blood pressure, or heartburn, you may find that you are more comfortable drinking less coffee per day. 


(1) “Coffee Consumption U.S. 2018/2019.” Statista,

(2) Saad, Lydia. “Americans’ Coffee Consumption Is Steady, Few Want to Cut Back.”, Gallup, 23 Apr. 2019,

(3) Bruce, Malcolm S., and M. Lader. “Caffeine abstention in the management of anxiety disorders.” Psychological medicine 19.1 (1989): 211-214.

(4) Yang, Amy, Abraham A. Palmer, and Harriet de Wit. “Genetics of caffeine consumption and responses to caffeine.” Psychopharmacology 211.3 (2010): 245-257.

(5) James, Jack E. “Critical review of dietary caffeine and blood pressure: a relationship that should be taken more seriously.” Psychosomatic medicine 66.1 (2004): 63-71.

(6) Köksal, Eda, et al. “Relationship between dietary caffeine intake and blood pressure in adults.” International journal of food sciences and nutrition 68.2 (2017): 227-233.

(7) Zhang, Zhenzhen, et al. “Habitual coffee consumption and risk of hypertension: a systematic review and meta-analysis of prospective observational studies.” The American journal of clinical nutrition 93.6 (2011): 1212-1219.

(8) McRorie Jr, Johnson W. “Heartburn: Lifestyle Modifications and Over-the-Counter Medications.” Nutrition Today 53.1 (2018): 18-25.

(9) Thomas, Fred B., et al. “Inhibitory effect of coffee on lower esophageal sphincter pressure.” Gastroenterology 79.6 (1980): 1262-1266.

(10) Maughan, Ron J., and J. Griffin. “Caffeine ingestion and fluid balance: a review.” Journal of human nutrition and dietetics 16.6 (2003): 411-420.

(11) Wikoff, Daniele, et al. “Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children.” Food and Chemical Toxicology 109 (2017): 585-648.

(12) Larsson, Susanna C., and Nicola Orsini. “Coffee consumption and risk of stroke: a dose-response meta-analysis of prospective studies.” American Journal of Epidemiology 174.9 (2011): 993-1001.

(13) Lopez-Garcia, Esther, et al. “Coffee Consumption and Coronary Heart Disease in Men and Women: A Prospective Cohort Study.” Circulation 111.14 (2005).

(14) Freedman, Neal D., et al. “Association of coffee drinking with total and cause-specific mortality.” New England Journal of Medicine 366.20 (2012): 1891-1904.

(15) Huxley, Rachel, et al. “Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis.” Archives of internal medicine 169.22 (2009): 2053-2063.

(16) Dulloo, A. G., et al. “Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers.” The American journal of clinical nutrition 49.1 (1989): 44-50.

(17) Arciero, PAUL J., et al. “Effects of caffeine ingestion on NE kinetics, fat oxidation, and energy expenditure in younger and older men.” American Journal of Physiology-Endocrinology and Metabolism 268.6 (1995): E1192-E1198.

(18) Bracco, David, et al. “Effects of caffeine on energy metabolism, heart rate, and methylxanthine metabolism in lean and obese women.” American Journal of Physiology-Endocrinology and Metabolism 269.4 (1995): E671-E678.

(19) Sinha, Rohit A., et al. “Caffeine stimulates hepatic lipid metabolism by the autophagy‐lysosomal pathway in mice.” Hepatology 59.4 (2014): 1366-1380.

(20) Pietrocola, Federico, et al. “Coffee induces autophagy in vivo.” Cell Cycle 13.12 (2014): 1987-1994.

(21) Maia, L., and A. De Mendonça. “Does caffeine intake protect from Alzheimer’s disease?.” European Journal of Neurology 9.4 (2002): 377-382.

(22) Liu, Qing-Ping, et al. “Habitual coffee consumption and risk of cognitive decline/dementia: A systematic review and meta-analysis of prospective cohort studies.” Nutrition 32.6 (2016): 628-636.

About the Author

Dr. Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.

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