Is It True That Coffee Cause Stomach Problems?

Vietnamese Coffee Exporter
coffee cause stomach problems

Coffee Cause Stomach Problems: Decades of scientific scrutiny have shed light on coffee’s potential to bolster health, a consensus supported by both medical professionals and dietitians. The beverage’s rich antioxidant profile is lauded for its role in extending life spans and diminishing the risk of various ailments, among other advantages.

Nonetheless, evidence also points to the less savory repercussions of caffeine consumption in excess. These undesirable effects encompass a quickened heartbeat, insomnia, migraines, and gastrointestinal discomfort.

Focusing on the digestive angle, what specific elements of coffee trigger these issues? Moreover, are there strategies to circumvent such digestive disturbances?

To delve deeper into this, I engaged with a trio of coffee experts. Continue reading to uncover their insights.


An exploration into the vast world of coffee reveals that its consumption in substantial quantities can be a catalyst for stomach discomfort, with caffeine taking center stage as a primary provocateur.

Caffeine, the ubiquitous stimulant found in coffee, tea, cocoa, and yerba maté, energizes the brain and central nervous system, staving off weariness by impeding adenosine—a neurotransmitter that signals fatigue.

Yet, the coin of caffeine’s effects has another side. While moderate consumption can sharpen alertness and ward off lethargy, excessive intake may have the opposite impact on health.

Coffee connoisseur and Q-grader with a doctorate in Food Science, Verônica Belchior, elucidates caffeine’s classification as a psychoactive agent due to its pronounced influence on cerebral function.

coffee cause stomach problems
“A modest dose, around 50mg, might alleviate anxiety,” Verônica notes. “However, elevated doses ranging from 150mg to 450mg could heighten anxiety, nervousness, and restlessness.”

“A modest dose, around 50mg, might alleviate anxiety,” Verônica notes. “However, elevated doses ranging from 150mg to 450mg could heighten anxiety, nervousness, and restlessness.”

She further cautions that regular caffeine consumption could lead to physiological reliance, and a sudden reduction might trigger withdrawal symptoms, including fatigue, diminished alertness, compromised concentration, mood fluctuations, headaches, and notably, nausea or stomach maladies.

A 1998 study indicated that caffeinated coffee could excite colonic activity by 23% more than its decaffeinated counterpart, and additional research has linked heightened caffeine levels to increased gastric acid production, precipitating digestive discomfort, particularly in individuals with heightened sensitivity to caffeine.

But what about other coffee constituents?

Beyond caffeine, coffee harbors several other elements that could wreak havoc on digestion. Verônica points out the potential adversity of coffee’s low pH for those prone to gastritis—a condition marked by stomach lining inflammation leading to indigestion and nausea.

Sebastian Opitz, Head of Green Coffee at the Coffee Excellence Centre at Zurich University of Applied Sciences, suggests the relationship between coffee and stomach woes is intricate.

“In our chemical explorations of green coffee,” Sebastian reveals, “our attention was drawn to a subset of lipids known as tryptamides—specifically alkanoyl tryptamides. These compounds, residing in the green coffee bean’s waxy outer layer, are implicated in the upsurge of gastric acid secretion.”

coffee cause stomach problems
He also notes that while catechol and pyrogallol, bitter-tasting compounds in green coffee, may boost gastric acid production, their trace presence likely renders their impact on stomach health negligible.

He also notes that while catechol and pyrogallol, bitter-tasting compounds in green coffee, may boost gastric acid production, their trace presence likely renders their impact on stomach health negligible.

Research on chlorogenic acids and trigonelline’s role in gastric acid secretion presents a paradox, with studies offering contradictory findings on whether they exacerbate or alleviate acid production.

The susceptibility to coffee-induced digestive issues does not seem to discriminate by cultural, ethnic backgrounds, or demographic factors such as age or gender. Chahan Yeretzian, also at the Coffee Excellence Centre, reports that gastric reflux—often manifesting as heartburn—is the predominant complaint among coffee drinkers with stomach sensitivities.

Nevertheless, Chahan acknowledges the scarcity of concrete evidence linking coffee consumption to gastric reflux, suggesting that individual variability might play a significant role and that genetic factors, while speculative, cannot be discounted.

In the quest to understand coffee’s impact on our digestive well-being, it is clear that personal thresholds and physiological responses take precedence, and what remains is a complex brew of factors yet to be fully distilled.


It’s a common belief that all green coffee beans share identical chemical profiles, but in reality, numerous factors can alter their chemical makeup. These factors encompass diverse sensory experiences, varying processing techniques, the degree of roasting, and the methodologies employed in brewing.

Sensory Profile: Each coffee possesses a distinct sensory signature and flavor palette. For instance, certain coffees may have a higher concentration of bitter compounds or a more accentuated level of acidity.

Chahan sheds light on the presence of bitter taste receptors not only in the oral cavity but also within the stomach and additional organs like the gallbladder.

“A 2017 study discovered that when these stomach receptors detect caffeine—a bitter compound—the stomach responds by rapidly secreting gastric acid,” Sebastian explains. This phenomenon helps to understand why bitter compounds can be linked with gastric irritation.

“The stomach perceives bitterness from caffeine as a signal to eliminate a potentially harmful substance,” he continues. “The swift response of releasing gastric acid serves to break down what the body interprets as ‘toxic.'”

However, the link between coffee’s acidity and bodily acidity appears tenuous.

“There’s a common misconception that the acidity in coffee leads to increased acidity in the body, thereby making acidic coffee detrimental to health,” Sebastian clarifies. “Yet this is not accurate. While there’s a correlation, causality is absent. Despite coffee’s acidic nature, typically with a pH of around five, it’s significantly less acidic than stomach gastric acid, which has a pH level below two.”

In essence, coffee’s acidity has a negligible effect on stomach acid levels.

“People often associate heartburn after coffee consumption with the beverage’s acidity,” Sebastian notes. “But numerous compounds in coffee trigger a rise in gastric acid secretion in the stomach.

“A 2010 study identified various compounds responsible for this,” he continues. “An increase in acid secretion lowers the stomach’s pH, which could potentially lead to heartburn.”

Roast Profile: Roasting transforms coffee beans on a cellular level and alters their chemical constituents.

“Typically, green coffee beans are rich in chlorogenic acids,” says Sebastian. “However, the roasting process reduces these levels by approximately half.”

The roast level also influences other compounds that could cause digestive discomfort.

“Put simply, opting for a darker roast may be preferable for those with sensitive stomachs,” he advises. “Roasting alters the levels of tryptamides, so darker roasted beans contain fewer of these compounds, potentially reducing gastric acid secretion and minimizing stomach issues.”

Yet, he points out that darker roasts may increase the presence of bitter compounds like lindanes and chlorogenic lactones, necessitating further research to ascertain their effects on gastric acid secretion.

Brewing Method: The brewing technique profoundly impacts the concentration of tryptamides in coffee.

“Espresso and French press methods often extract more tryptamides,” Sebastian informs. “Conversely, filter coffee typically has lower tryptamide levels due to absorption by the paper filter.

“Nonetheless, tryptamides are merely one group of compounds influencing gastric acid secretion,” he adds. “Our ongoing research also examines chlorogenic acids’ effects on the stomach, though conclusive evidence is forthcoming.”

Processing Method: The way coffee is processed significantly shapes both its flavor profile and chemical composition.

“Natural processing methods usually result in higher tryptamide levels,” Sebastian observes. “But when we look at Monsoon Malabar or wet-hulled coffees, the concentrations diminish.

“Further investigation is required, but extended fermentation periods might reduce tryptamide content,” he speculates. “This could be due to the coffee’s outer waxy layer being exposed to environmental elements for a longer duration.”


Given that caffeine, as well as several other constituents in coffee, can be problematic for some individuals’ stomachs, one might wonder if decaffeinated coffee presents a gentler alternative.

“Decaffeinated coffee might indeed be a more suitable choice for those who find themselves sensitive to caffeine,” suggests Verônica. “Nevertheless, the effects of caffeine on an individual also hinge on various factors such as age, body weight, and overall health.”

Sebastian points out that the decaffeination technique itself can influence the chemical makeup of the coffee bean.

“In our analysis of different decaffeination methods, including carbon dioxide (CO2), chloromethane, and Swiss Water processes, we observed distinct impacts on the chemical structure of the beans,” he explains. “The ‘gentler’ methods, notably the CO2 method, managed to extract nearly all the caffeine while retaining most other compounds found in green coffee.

“The CO2 process resulted in beans that were somewhat darker yet still maintained the characteristic green tint of unroasted coffee,” he continues. “Conversely, the chloromethane and Swiss Water processes led to more uneven, brownish-colored beans, suggesting a more pronounced alteration of the green coffee’s exterior layer.

“This could imply a reduction in tryptamide levels,” Sebastian hypothesizes. “Consequently, decaffeinated coffee, particularly those processed with milder methods, may indeed be less likely to induce stomach discomfort compared to their caffeinated counterparts.”

On the Topic of Marketing “Stomach-Friendly” Coffee:

Although studies have pointed out that certain coffee components can lead to gastric distress, Chahan observes a lack of market demand for “stomach-friendly” coffee options.

“For example, major coffee corporations have not yet introduced a ‘stomach-friendly’ line,” he remarks. “This suggests they don’t see a compelling amount of evidence to support such a claim, though perspectives on this may shift in the future.”

Sebastian also notes that coffee varieties naturally low in caffeine, like Laurina and Aramosa, might serve as viable alternatives for those particularly susceptible to caffeine’s effects.

“Exploring different varieties and species of coffee that naturally contain lower levels of caffeine could prove beneficial,” he concludes.

In summary, while coffee contains elements that can potentially lead to digestive discomfort, the extent of this effect is largely influenced by individual sensitivities and consumption levels.

While reactions to coffee can differ from one individual to another, drinking coffee in moderation generally does not lead to stomach issues.

By being more intentional about the timing and frequency of your coffee intake, you can minimize the chances of experiencing any adverse stomach reactions.