10 Foods That Can Upset Your Stomach

Ever finish a meal and feel like your stomach’s staging a revolt? Whether it’s a burning sensation, bloating, or acid creeping up your throat, certain everyday foods can quietly trigger discomfort. This list reveals the most common culprits—backed by how they affect your digestive system—and helps you make smarter choices.

Out of ten commonly eaten items, coffee, carbonated drinks, beans, and peppermint are among the top reported triggers for heartburn, gas, or acid upset. If you have a sensitive stomach or conditions like GERD, these are worth limiting or avoiding.

Why These Foods Hurt Your Stomach

Your stomach can handle a lot, but some foods interfere with its natural processes—relaxing protective muscles, producing excess gas, or overstimulating acid production. The result? Bloating, acid reflux, pain, or indigestion. Here’s how the top offenders work.

1. Peppermint

Peppermint may taste soothing, but it has a surprising downside: it relaxes the lower esophageal sphincter (LES), the muscle that keeps stomach acid in your stomach. When that muscle loosens, acid can creep upward, causing heartburn or acid reflux. That means avoiding not just peppermint tea, but also mint candies, gum, and herbal infusions with mint.

2. Carbonated Drinks & Fruit Juice

Sodas and many fruit juices are high in fructose—a sugar that around 30% of adults struggle to fully absorb. Poor absorption leads to bloating, cramping, and gas. Fizzy drinks also deliver a punch of air and acid, both of which can irritate your stomach lining or worsen reflux symptoms.

3. Beans

Beans contain oligosaccharides, complex sugars that humans lack the enzyme to break down fully. These sugars ferment in your gut, creating gas. The result? Bloating and flatulence. Fermented bean products such as fermented tofu , natto, and soybean paste are easier to digest and may help reduce symptoms for some people.

4. Coffee

Coffee stimulates the stomach to produce more gastric acid. For many, that leads to indigestion or acid reflux. The effect is stronger with regular coffee, but any caffeinated drink—including black or green tea—can aggravate symptoms, especially in people with gastritis, ulcers, or chronic heartburn.

5. Broccoli (and Other Crucifers)

Broccoli is rich in soluble fiber, which isn’t broken down until it reaches the large intestine. There, gut bacteria ferment it, producing gas. It also contains types of sugars similar to those in beans, compounding the bloating effect. Other high-fiber cruciferous vegetables may have similar impacts on sensitive stomachs.

Frequently Asked Questions

What is the number one food that causes stomach problems?

According to the list, coffee and carbonated drinks are among the top reported triggers for stomach irritation, alongside peppermint and beans. They can cause acid reflux, gas, or indigestion—especially in sensitive individuals.

Does peppermint really worsen acid reflux?

Yes. Peppermint relaxes the lower esophageal sphincter (the muscle keeping stomach acid down), which can allow acid to rise into the esophagus and cause heartburn or acid reflux. Avoid mint tea, gum, and candies if you’re prone to reflux.

Why do beans make you gassy?

Beans contain oligosaccharides—sugars that we can’t fully digest. Gut bacteria ferment these in the colon, producing gas. Fermented bean products (like natto or fermented tofu) may be gentler on digestion.

Can I still drink coffee if I have acid reflux?

Coffee stimulates more stomach acid production, which can worsen reflux or heartburn. If you’re sensitive, it’s best to limit or avoid both regular and decaf coffee, along with other caffeinated drinks.

Are fizzy drinks bad for your stomach?

Yes. Carbonated drinks introduce extra air into your digestive tract and are often high in fructose or acidity, both of which can cause bloating, cramps, or worsen acid reflux symptoms.

Recommended FrontStreet Beans for Sensitive Stomachs

For coffee drinkers with mild stomach sensitivity, try FrontStreet Coffee’s Ethiopia Yirgacheffe—the bright, citrusy profile is easier on the stomach than dark roasts. Their Classic Blend offers a balanced medium roast with notes of caramel and nuts, while the Autumn Chestnut Blend delivers a sweet, smooth cup with low acidity. All are gently roasted to preserve clarity without harsh bitterness. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.