What Happens To Your Body When You Cut Down To 1 Cup Of Coffee A Day

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If you're jittery, aren't sleeping well, and can't concentrate without a cup of coffee in your hand, you may be wondering about cutting back on your coffee consumption. According to a study in Critical Reviews In Food Science & Nutrition in 2018, 400mg of caffeine is the recommended daily limit for adults. This is about four cups of coffee, but many of us may ingest more.

"You find coffee on almost any street in any city anywhere in the world," Dr. David Cutler M.D., a family medicine physician at Providence Saint John's Health Center, tells Bustle. "Today, two-thirds of American adults have at least one cup of coffee daily." If you habitually drink more than that, but would like to cut back to just one delicious steaming cup per day, the effects on your health and body can be significant, experts tell Bustle.

It's a good idea to beware of blanket claims about the impact of cutting down on caffeine, though. "A degree of skepticism is needed when interpreting any claims about the benefits or risks of coffee," Dr. Cutler tells Bustle. "In addition to caffeine, there are many chemicals in coffee which can affect the body." Chemicals present in coffee include 3,5 dicaffeoylquinic acid, an antioxidant, and over 1,000 other compounds. How you take your coffee — with milk or sugar, for instance — can also affect the consequences of reducing your intake. "Some people are also more sensitive to the effects of caffeine," Dr. Anita Skariah, D.O., a primary care physician for UNC Health Care, tells Bustle.

This complexity means that it's very difficult to predict exactly how a one-coffee-a-day habit might affect you, but here are seven potential ways in which it could impact your health.

1. You May Experience Withdrawal Symptoms

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Depending on your coffee habit before you decide to stick to one cup a day, you may experience caffeine withdrawal — as you'll know if you've ever tried to stop drinking coffee cold turkey.

"For those who have developed an addiction to caffeine, stopping completely may produce symptoms," Dr. Skariah tells Bustle. "They should go away after two to nine days." The symptoms of caffeine withdrawal aren't dangerous, but they can be inconvenient and unpleasant. A 2004 study published in Psychopharmacology found that 10 symptoms are most commonly associated with caffeine withdrawal: headache, fatigue, decreased energy, decreased alertness, drowsiness, decreased contentedness, depressed mood, difficulty concentrating, irritability, and feeling foggy. The more coffee you drank before cutting back, the worse your symptoms may be.

However, the good news is that these symptoms will be dampened by your single cup a day — and they won't last. A study published in Sleep Medicine of 23 people who gradually reduced their caffeine intake to nothing found that after four weeks of caffeine-free life, their symptoms had disappeared — and their moods, sleep quality, and fatigue levels seemed to be better than they'd been when they started. And if you haven't been drinking much caffeine to begin with, you may not experience any issues at all.

2. It May Help Urinary Issues

One side effect of cutting back on caffeine, according to a 2019 review of caffeine withdrawal studies, is increased diuresis, or emptying your bladder. This is intriguing because caffeine's diuretic powers have been debated by scientists for some time. It seems that caffeine has a mild diuretic effect, meaning that it helps you pee more often. Restricting your intake can also make your body urinate more often, at least while you're adjusting to your new regime.

Less coffee in general is likely good news for your bladder. "Urinary problems are associated with coffee consumption," Dr. Cutler tells Bustle. A study in 2013 found that drinking a lot of coffee (more than 200mg a day) made women more likely to experience urinary incontinence. Reducing your coffee intake may mean you head to the toilet far less often once you've overcome withdrawal.

3. It Could Help Your Digestion

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People who drink a lot of coffee, Dr. Cutler tells Bustle, may be more likely to experience heartburn. Heartburn, or acid reflux, could be triggered by caffeine intake, but scientists aren't entirely clear on how. One of the first recommendations for people who have gastroesophageal reflux disease is cutting out caffeine, and if you drink a lot of coffee and experience heartburn regularly, it's likely that cutting down may ease your symptoms. However, if you experience acid reflux, it's probably a good idea to head to the doctor to track what might be causing it, as caffeine is unlikely to be the only culprit.

4. It May Alter Your Gut Microbiome

Researchers are only just discovering the effects of caffeine on the gut microbiome, which is composed of millions of bacteria and other living cells and helps us digest our food and protect against illness. A study in 2019 found that when rats were introduced to coffee, their gut microbiomes changed and they pooped more frequently — but it wan't clear that caffeine itself was the cause. Coffee itself doesn't make us poop; that's an old myth that's been disproved. However, it may affect our digestion in other ways. A lot more research needs to be done on how coffee might alter your gut microbiome, and how cutting back might shift its composition and affect your health.

Dr. Cutler tells Bustle that for some people, coffee can make bowel issues worse, so if you have a history of bowel problems, cutting back with your physician's guidance might be a good plan. A 2016 study also found that a higher caffeine intake can increase colorectal cancer risk in women, which is another persuasive argument for cutting back.

5. Your Sleep Might Improve

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If you've been having difficulty sleeping or aren't waking up feeling particularly rested, lowering your caffeine intake to a lower dose may have substantial effects on your sleep cycle. "Cutting back can improve sleep and restlessness," Dr. Skariah tells Bustle. "Caffeine’s metabolites can remain in your system long after the buzz goes away, and can keep you awake at night too." Caffeine's stimulant effect may make it easier to wake up in the mornings, but if you stick to that one cup in the mornings, your body may find it easier to fall asleep at night, and you may get up feeling more rested.

6. You May Notice Differences In Your Mood

Lowering caffeine levels can also reduce anxiety, Dr. Skariah says. "You may not have even realized that caffeine was the culprit," she tells Bustle. A study of nearly 3,000 teenagers in 2015 found that high caffeine consumption was linked to stress, anxiety and depression, while the 2015 textbook Coffee in Health & Disease Prevention noted that people with anxiety disorders seem to be particularly vulnerable to the effects of caffeine. If you've been diagnosed with an anxiety issue before or suspect you have the symptoms of an anxiety disorder, talk to your doctor or therapist about how to manage your caffeine intake.

7. You Can Still Reap Health Benefits From Coffee

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Coffee in moderate amounts has been shown to be pretty helpful. "A lower risk of diabetes, stroke and certain cancers is clearly associated with drinking coffee," Dr. Cutler tells Bustle. A 2017 review of coffee and health published in Autoimmunity Reviews also found that coffee can also help protect some people against multiple sclerosis, ulcerative colitis, and other autoimmune conditions. Clearly a little bit of coffee can go a long way.

"The good news is that small amounts of coffee seem to generate many of the benefits, while larger amounts seem to bring on the greatest risk," Dr. Cutler says. "So a very sensible approach is to limit your coffee to one cup per day."

Right now, studies on caffeine and the human body continue to evolve. Coffee has been part of the human diet for thousands of years in some parts of the world, and we're still figuring out the ideal way to drink it to help our health. Cutting back to one cup a day, says Dr. Cutler, appears to be a sustainable way to reap the benefits of coffee without the health risks. "Maybe in another thousand years we will know if this is the best advice," he says. Just remember that even decaf has a small amount of caffeine in it.

Studies cited:

(2009). Advances in GERD: Current Developments in the Management of Acid-Related GI Disorders. Gastroenterology & Hepatology, 5(9), 613–615.

Gleason, J. L., Richter, H. E., Redden, D. T., Goode, P. S., Burgio, K. L., & Markland, A. D. (2013). Caffeine and urinary incontinence in US women. International urogynecology journal, 24(2), 295–302. doi:10.1007/s00192-012-1829-5

Groessl, E., Allison, M.A., Larson, J.C. et al. (2016) Coffee Consumption and the Incidence of Colorectal Cancer in Women. Journal of Cancer Epidemiology. 6918431. https://doi.org/10.1155/2016/6918431.

Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl). 2004 Oct;176(1):1-29.

Lack L., Johannson, K. (2013) Caffeine withdrawal: Cost or benefit? Sleep Medicine 14.1 e53

Richards, G., & Smith, A. (2015). Caffeine consumption and self-assessed stress, anxiety, and depression in secondary school children. Journal of psychopharmacology (Oxford, England), 29(12), 1236–1247. doi:10.1177/0269881115612404

Sajadi-Ernazarova KR, Hamilton RJ. (2019) Caffeine, Withdrawal. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

Sharif K, Watad A, Bragazzi NL, Adawi M, Amital H, Shoenfeld Y. (2017) Coffee and autoimmunity: More than a mere hot beverage! Autoimmun Rev. 2017 (7):712-721. doi: 10.1016/j.autrev.2017.05.007.

Verster, J.C. & Koenig, J.(2018) Caffeine intake and its sources: A review of national representative studies. Critical Reviews in Food Science and Nutrition. 58:8, 1250-1259. doi: 10.1080/10408398.2016.1247252

Vinader-Caerols, C., Monleón, S., Parra, A. (2015) Chapter 50 - Coffee and Anxiety. In V.R. Preedy (Ed.), Coffee in Health and Disease Prevention (pp.449-455). Academic Press https://doi.org/10.1016/B978-0-12-409517-5.00050-4.

Zhang, Y., Chen, S-H. (2013) Effect of Coffee on Gastroesophageal Reflux Disease. Food Science and Technology Research. 19. doi: 10.3136/fstr.19.1

Zhang, Y., Lee, E. T., Cowan, L. D., Fabsitz, R. R., & Howard, B. V. (2011). Coffee consumption and the incidence of type 2 diabetes in men and women with normal glucose tolerance: the Strong Heart Study. Nutrition, metabolism, and cardiovascular diseases : NMCD, 21(6), 418–423. doi:10.1016/j.numecd.2009.10.020

Experts:

Dr. David Cutler M.D., family medicine physician at Providence Saint John's Health Center

Dr. Anita Skariah, D.O., primary care physician for UNC Health Care