Why Does Coffee Make Me Nauseous?

Acids contained in coffee can irritate the lining of your stomach and make you feel nauseous — especially if your stomach is empty. Here’s what you can do about it…

September 25, 2024
Milk being poured to a cup full of coffee

For millions of people around the world, a morning routine just isn’t complete until they take those first few sips of coffee. 

For some reason, every now and then, that morning cuppa leaves you feeling more queasy than energized… 

Sound familiar?

In this post, we’ll explore exactly why this happens and offer a few tips you can use to avoid this issue entirely.

4 Reasons Why Coffee Makes You Feel Nauseous

There could be reasons beyond these four (maybe the creamer you used was expired) — but these are among the most common. 

We’ll also give you ideas on what can help so you can enjoy your coffee in peace.

1. You’re Sensitive to Caffeine

One of the most common causes of coffee-related nausea is caffeine sensitivity. As a stimulant, caffeine speeds up digestion, which makes your digestive system work harder and faster and can increase stomach acid production. 

Additionally, caffeine may cause jitteriness and anxiety, both of which can contribute to nausea [1].

Caffeine lasts about 6 hours for most users; however, people who are sensitive to caffeine could continue to feel the effects for 8 or even 10 hours later.

If you have a high caffeine sensitivity, you may experience one or more of the following symptoms:

  • Headaches
  • Anxiety
  • Lack of sleep
  • Heart palpitations
  • Tremors
  • Dehydration
  • Increased heart rate

→ Learn more about how to test for caffeine sensitivities at the bottom of this article.

What You Can Do About Caffeine Sensitivities:

There’s good news… just because you’re sensitive to caffeine doesn’t mean you have to cut coffee out of your life completely.

In most cases, cutting back on coffee intake or simply diluting your coffee with low-caffeine ingredients like decaf coffee, chicory root coffee, or mushroom coffee will eliminate this issue.

Try mixing half of your normal coffee with either decaf or a coffee alternative. You can still enjoy your morning cuppa with half or less caffeine than usual.

2. Acidic Compounds Are Irritating Your Stomach Lining 

Coffee has a pH of 4.85 to 5.10, making it slightly acidic. Coffee beans contain various naturally occurring acids, including chlorogenic, malic, citric, and acetic acid, which can irritate your stomach lining. This can lead to digestive issues like nausea, acid reflux, or heartburn. 

What You Can Do About Acidic Coffee:

If you think the acids could be causing stomach problems, try switching to a coffee that’s less acidic — usually beans that are grown at lower altitudes. Robusta coffees, like our HaNoi and BanMe, have a strong flavor and higher caffeine but less acidic components overall. These coffees are much more gentle on sensitive stomachs. 

If you don’t want the bold taste of robusta, try making cold brew coffee from a high-quality arabica, such as our DaLat. Because cold brew is made without heat, it extracts less of these acidic components. Cold brew coffees are notoriously gentle and preferred by people sensitive to more acidic coffees.

3. You’re Dehydrated

Coffee is a diuretic, meaning it stimulates your kidneys and causes them to release water and salt through urination. While it’s not usually an issue, it can be If you aren’t getting enough water. 

This can create an imbalance that reduces the blood flow to your stomach, resulting in dehydration that can slow digestion, causing nausea and other signs of gastrointestinal distress [5]. 

What You Can Do About Caffeine Dehydration:

Of all of the problems in life, this one is pretty straightforward — drink more water. If you’re more dehydrated than usual, take electrolytes to replenish lost salts. 

Not only will you be able to drink coffee with fewer issues, you’ll feel better overall!

4. The Coffee Is Interacting With Your Medications

Some medications — particularly anti-depressants, antidiabetics, and respiratory medications — can interact with the compounds in coffee, affecting how the medicine is absorbed and metabolized [6].

This can either increase the effects of your medications or prevent them from working altogether [7]. As a result of the improper medication, you might feel a wide range of negative effects, including nausea, shortness of breath, and heart palpitations.

What You Can Do About Caffeine Drug Interactions:

If it's even a slight possibility that caffeine is interacting with your medication to make you feel nauseous, talk to your doctor right away and stop drinking coffee. These symptoms could be an indicator of a more serious issue.

Related: Why Does Coffee Make You Poop?

How to Prevent Nausea from Coffee

Ingredients for a good cup of coffee that doesn't give you nausea

Now that you know what causes coffee nausea, you’re probably wondering how to prevent it. Fortunately, there are a few simple solutions. 

6 Tips to Avoid Feeling Nauseous After Drinking Coffee:

  1. Stay hydrated — To prevent dehydration and lessen your chances of stomach irritation, ensure you drink plenty of water throughout the day. You can also try drinking a glass of water before and after your coffee. 
  2. Brew a weaker cup — If you find that strong coffee upsets your stomach, try brewing a weaker cup. Depending on your brewing method, this might include using fewer grounds or adding more milk or water to your coffee. 
  3. Experiment with different additives — For some people, switching to plant-based milk and creamers can decrease stomach upset. Make your own creamer for ultimate control over the ingredients.
  4. Drink less coffee — If you regularly find yourself reaching for four or more cups daily, try cutting down to just one or two. It’ll help if you find other ways to stay energized. Then over time, you can slowly start incorporating more coffee into your routine. 
  5. Don’t drink on an empty stomach — As a general rule, avoid drinking coffee on an empty stomach. Instead, have a small snack or meal beforehand. That will create a buffer between your stomach and the coffee's acid and lessen your chances of nausea. 
  6. Opt for a different roast — Switching to a decaffeinated or less acidic roast can reduce discomfort and ensure your coffee remains pain-free. There are even low-acid coffee blends specifically formulated to be gentler on your stomach.

Related: Caffeine Uses, Risks, & Long-Term Effects

How to Test for Caffeine Sensitivity

One of the most accurate ways to know if you have a sensitivity to caffeine is to do an at-home test. There are plenty of tests available online that can determine whether you’re a rapid caffeine metabolizer or a sluggish one. Popular genetic tests like 23 and Me will test for this too.

The tests are simple — collect a small amount of your saliva on a swab and send it to a lab to be tested. A professional team will analyze your sample and look for specific DNA markers to reveal how efficiently your body breaks down caffeine. 

Alternatively, you can keep a detailed food log to discover exactly how much caffeine you’re consuming and how it affects you. Study the label of everything you eat and drink, and make a note of how much caffeine each portion contains.

Write down how much caffeine you consume and any symptoms. After a couple of weeks, you should be able to find a pattern and determine if you’re especially sensitive to caffeine. 

What Causes Caffeine Sensitivities

There are several factors that can cause caffeine sensitivity, and they all impact CYP1A2, an enzyme responsible for approximately 95% of caffeine metabolism.

Variants of this enzyme, CYP1A21A (associated with fast metabolism) and CYP1A21F (associated with slow metabolism), are responsible for how fast caffeine is broken down and cleared from your bloodstream [2]. 

The enzymes responsible for caffeine metabolism don’t just affect the concentration of caffeine in your blood — they also influence cortisol, adrenaline, and glucose levels [3]. 

The most common risk factors for caffeine sensitivity include:

  • Genetics — If you produce only small amounts of CYP1A2, your liver won’t effectively metabolize caffeine. 
  • Gender — CYP1A2 activity is lower in women than men, meaning women are more likely to have caffeine sensitivity.
  • Age — The older you get, the less efficient your CYP1A2 enzyme becomes. This means that you can develop caffeine sensitivity later in life.
  • Pregnancy — Increased estrogen when pregnant inhibits CYP1A2 action, increasing the chances of developing caffeine sensitivity.
  • Birth control pills — Some contraceptive pills reduce the action of CYP1A2, slowing your caffeine metabolism.

Related: Why Doesn't Caffeine Affect Me?

FAQs: Coffee Nausea 

Transformation of coffee, from beans to the cup.

Still have questions? In this section, we’ll take a closer look at why your coffee is making you nauseous and what you can do to stop it. 

1. What brewing methods are less likely to cause nausea? 

Not all brewing methods are created equal. While some create bold, intensely flavored cups of coffee, others make cuppas that are smoother, less caffeinated, and less acidic. Some of the brewing methods least likely to cause stomach issues include: 

Related: How Much Caffeine is in Different Kinds of Coffee

2. Will adding milk or creamer reduce nausea? 

For some people, adding milk or creamer to your coffee can help prevent stomach upset. However, this depends on the type of additive used. Some can be hard to digest and cause irritation — particularly if you’re lactose intolerant. 

Make sure the coffee creamer is fresh and not a source of stomach discomfort.

3. Is cold brew coffee less likely to make you nauseous? 

While it ultimately comes down to the bean and roast type, cold brew is generally less likely to cause nausea. Because of the brewing process, cold brew coffee contains less caffeine and acid than traditional, hot-brew coffee. It’s also smoother and much more gentle on your digestive tract. 

4. Should you drink coffee if you’re feeling sick?

The answer to whether or not you should drink coffee while sick is two-fold. On one hand, coffee can dehydrate you and exacerbate symptoms like vomiting and diarrhea. But it's not all bad news. Coffee also has anti-inflammatory compounds and antioxidants that can help combat illness [8]. 

The caffeine boost can also reduce fatigue and keep you functioning like normal. So, for mild symptoms, it’s safe to drink coffee in moderation. But if you’re severely under the weather, health experts recommend avoiding coffee until you’re on the mend.

5. Can switching to decaf prevent nausea?

While decaf coffee contains trace amounts of caffeine, it’s significantly less than traditional coffee. As a result, decaf is less likely to cause nausea. But, if you don’t want to give up caffeine completely, you can dilute your regular coffee with equal parts decaf or alternate cups. 

References 

  1. Willson C. The clinical toxicology of caffeine: A review and case study. Toxicology Reports. 2018;5:1140-1152. doi: https://doi.org/10.1016/j.toxrep.2018.11.002
  2. Marilyn C Cornelis, Ahmed El-Sohemy, Edmond K Kabagambe, Hannia Campos. (2006). Coffee, CYP1A2 Genotype, and Risk of Myocardial Infarction.
  3. Sung, PhD, Andrea S. Vincent, PhD, Michael F. Wilson, MD. (2008). Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels.
  4. Steinbrook, R. A., Garfield, F., Batista, S. H., & Urman, R. D. (2013). Caffeine for the prevention of postoperative nausea and vomiting. Journal of Anaesthesiology Clinical Pharmacology, 29(4), 526-529.
  5. Nehlig A. Effects of Coffee on the Gastrointestinal Tract: a Narrative Review and Literature Update. Nutrients. 2022;14(2):399. doi: https://doi.org/10.3390/nu14020399
  6. Broderick, P. J., Benjamin, A. B., & Dennis, L. W. (2005). Caffeine and psychiatric medication interactions: a review. The Journal of the Oklahoma State Medical Association, 98(8), 380-384. https://pubmed.ncbi.nlm.nih.gov/16206866/
  7. Belayneh A, Molla F. The Effect of Coffee on Pharmacokinetic Properties of Drugs: A Review. BioMed Research International. 2020;2020. doi: https://doi.org/10.1155/2020/7909703
  8. Liang N, Kitts D. Antioxidant Property of Coffee Components: Assessment of Methods that Define Mechanisms of Action. Molecules. 2014;19(11):19180-19208. doi: https://doi.org/10.3390/molecules191119180