I love coffee. Every version of it; black, white, iced, frothed. Whatever version it may be, it sparks joy in me and quite simply, I enjoy the addiction.

But naturally, as a nutrition student, I was curious about its impacts on my health. I had so many questions!

Is coffee a diuretic? Does coffee dehydrate me? Are there health benefits to consuming coffee?

(Short answer is kind of, no and yes.) Watch my video if you don’t feel like reading.

Is coffee a diuretic?

Well, a study conducted by The University of Birmingham showed that the diuretic effect, or urine promoting effect, was very little. (Killer-1) But I also found another study that showed that coffee does have a diuretic effect when consumed in large doses, which is about five cups. However, this diuretic effect is reduced for habitual coffee drinkers. (Fisher-3)

In summary, coffee is probably not the cause of those extra trips to the bathroom, unless you’re drinking more than five cups.

Does coffee dehydrate?

The same study I mentioned earlier (The University of Birmingham) also made discoveries on the hydration qualities of coffee. They studied fifty males who habitually drank between 3-6 cups of coffee a day and found that when they consumed coffee in moderation, it provided similar hydrating qualities as water. (Killer-1)

That’s a jaw-dropper for me. I was always under the impression that coffee dehydrated me and this notion was reinforced by the aftertaste of coffee. My mouth always felt a bit drier a bit parched. I looked into this further, and this sensation can probably be attributed to the Tannin in coffee. Tannins are a type of chemical compound that are present in coffee, wine and teas and they are known to give an “oral sensation of astringency and bitterness.” (Combs-2)

So, if you’re drinking black coffee, it’s almost as if you’re drinking a cup of water! That’s a win for me.

Does coffee have any health benefits?

Coffee consumption has been shown to be correlated with longer telomeres. (Cardin-4)

If you’re not familiar with telomeres, they are an essential component of our cells and they directly effect how our cells age.

Short telomeres are associated with skin aging, bone loss, graying hair, heart disease, lung disease, Alzheimer’s, etc. (Blackburn- 5)

So, theoretically, if coffee keeps our telomeres long, it would also prolong the manifestation of these diseases and symptoms of aging.

“After the period of drinking coffee, the patients [of the study] had significantly longer telomers and lowered oxidative stress in their blood than their control group. Further, in a sample of over four thousand woman, those who drank caffeinated coffee (but not decaffeinated) were likely to have longer telomers.

“The Telomere Effect” Book by Elissa Epel and Elizabeth Blackburn

It’s important to note that all these studies are talking about black coffee. Not the sugared milk concoction with a couple shots of espresso we’re all guilty of consuming.

Also, in writing this article, I set out to prove to myself that coffee is not as bad as I thought it was. That confirmation bias, and my desire to keep this post short and interesting, led me to leave out all the gritty details of the negative side effects of coffee.

Caffeine is not without fault. It is an addictive substance, with unpleasant withdrawal symptoms (Sports RD-6).

However, as far as addictions go, it is my personal opinion that the benefits outweigh the disadvantages.

Thanks for reading and be well,

Sources

1. Killer SC, Blannin AK, Jeukendrup AE. No Evidence of Dehydration with Moderate Daily Coffee Intake: A Counterbalanced Cross-Over Study in a Free-Living Population. PLoS ONE. 2014;9(1):1-8. doi:10.1371/journal.pone.0084154

2. Combs CA. Tannins : Biochemistry, Food Sources and Nutritional Properties. Nova Science Publishers; 2016. Accessed August 19, 2020. http://search.ebscohost.com.libproxy.txstate.edu/login.aspx?direct=true&db=cat00022a&AN=txi.b4390916&site=eds-live&scope=site

3. Fisher SM, McMurray RG, Berry M, Mar MH, Forsythe WA (1986) Influence of caffeine on exercise performance in habitual caffeine users. Int J Sports Med 7: 276–280.

4. Cardin, R., et al., “Effects of Coffee Consumption in Chronic Hepatitis C: A Randomized Controlled Trial,” Digestive and Liver Disease 45, no. 6 (June 2013): 499–504, doi:10.1016/j.dld.2012.10.021.

5. Blackburn, Dr. Elizabeth. The Telomere Effect: A Revolutionary Approach to Living Younger, Healthier, Longer (p. vi). Grand Central Publishing. Kindle Edition.

6. Sports RD https://www.sportsrd.org/wp-content/uploads/2018/11/Caffeine_and_Athletic_Performance_WEB.pdf