Coffee is such a popular beverage that its consumption levels come second only to water in some countries (1).
In addition to helping you feel less tired and more alert, the caffeine in coffee may improve your mood, brain function, and exercise performance. It may also boost weight loss and protect against illnesses like type 2 diabetes, Alzheimer’s, and heart disease (2, 3).
Many people enjoy drinking coffee first thing in the morning. Yet, some people assert that having it on an empty stomach may harm your health.
This article discusses whether you should drink coffee on an empty stomach.
Share on PinterestCouple drinking coffeeDoes it cause digestive issues?
Research shows that coffee’s bitterness may stimulate the production of stomach acid (4, 5).
As such, many people believe that coffee irritates your stomach, worsens symptoms of gut disorders like irritable bowel syndrome (IBS), and causes heartburn, ulcers, nausea, acid reflux, and indigestion.
Some suggest that drinking your cup of joe on an empty stomach is particularly harmful since there’s no other food present to prevent the acid from damaging your stomach lining.
Yet, research fails to find a strong link between coffee and digestive troubles — regardless of whether you drink it on an empty stomach (6).
While a small proportion of people are extremely sensitive to coffee and regularly experience heartburn, vomiting, or indigestion, the frequency and severity of these symptoms remain constant regardless of whether they drink it on an empty stomach or with food (7).
Still, it’s important to pay attention to how your body responds. If you experience digestive issues after drinking coffee on an empty stomach but not when drinking it with a meal, consider adjusting your intake accordingly.
summaryCoffee increases the production of stomach acid but doesn’t appear to cause digestive issues for most people. Therefore, drinking it on an empty stomach is perfectly fine.
Does it raise stress hormone levels?
Another common argument is that drinking coffee on an empty stomach may increase levels of the stress hormone cortisol.
Cortisol is produced by your adrenal glands and helps regulate metabolism, blood pressure, and blood sugar levels. Yet, chronically excessive levels can trigger health problems, including bone loss, high blood pressure, type 2 diabetes, and heart disease (8).
Cortisol levels naturally peak around the time you wake up, decline over the day, and peak again during the early phases of sleep (9).
Interestingly, coffee stimulates cortisol production. Thus, some people claim that drinking it first thing in the morning, when cortisol levels are already high, can be dangerous.
However, cortisol production in response to coffee appears much lower among people who drink it regularly, and some studies show no rise in cortisol at all. Plus, there’s little evidence to suggest that drinking coffee on a full stomach reduces this response (9, 10).
What’s more, even if you don’t drink it often, any increase in cortisol levels seems to be temporary.
There’s little reason to believe that such a brief peak would result in long-term health complications (9).
In short, the negative effects of chronically high levels of this hormone are more likely to result from a health disorder like Cushing’s syndrome than from your coffee intake.
summaryCoffee may cause a temporary rise in the stress hormone cortisol. Nonetheless, this is unlikely to result in health problems, regardless of whether you drink it on an empty stomach or with food.
Other potential side effects
Coffee may also have a few negative side effects, regardless of whether you drink it on an empty stomach.
For instance, caffeine can be addictive, and some people’s genetics may make them particularly sensitive to it (11, 12).
That’s because regular coffee intake can alter your brain chemistry, requiring progressively larger amounts of caffeine to produce the same effects (13).
Drinking excessive amounts may lead to anxiety, restlessness, heart palpitations, and worsened panic attacks. It may even result in headaches, migraines, and high blood pressure in some individuals (1, 14, 15).
For this reason, most experts agree that you should cap your caffeine intake at around 400 mg per day — the equivalent of 4–5 cups (0.95–1.12 liters) of coffee (16, 17).
Since its effects can last up to 7 hours in adults, coffee may also disrupt your sleep, particularly if you drink it late in the day (1).
Finally, caffeine can easily cross the placenta, and its effects can last up to 16 hours longer than usual in pregnant women and their babies. Hence, pregnant women are encouraged to limit their coffee intake to 1–2 cups (240–480 ml) per day (1, 18).
Keep in mind that drinking coffee on an empty stomach doesn’t appear to affect the strength or frequency of these effects.
summaryDrinking too much coffee may cause anxiety, restlessness, migraines, and poor sleep. However, no evidence indicates that drinking it on an empty stomach affects the frequency or strength of these side effects.
The bottom line
Many people enjoy coffee first thing in the morning before they’ve eaten.
Despite persistent myths, little scientific evidence suggests that drinking it on an empty stomach is harmful. Rather, it likely has the same effects on your body no matter how you consume it.
All the same, if you experience digestive issues when drinking coffee on an empty stomach, try having it with food instead. If you notice an improvement, it may be best to adjust your routine accordingly.