If a cup of coffee is the first thing you reach for after waking up, you’re not alone. According to the National Coffee Association, as many as 9 in 10 coffee drinkers start their day with a steamy cup of joe — often before taking a bite of toast or cereal.
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But could that hot brew on an empty stomach be bad for your health? Probably not, says registered dietitian Anthony DiMarino, RD, LD.
“Your digestive system is incredibly complex and efficient,” he says. “Most people don’t have any problem drinking coffee on an empty stomach.”
DiMarino debunks two common myths and shares why it’s OK to enjoy that cuppa without any food.
Gastroesophageal reflux disease (GERD) happens when a valve between your stomach and esophagus (food pipe) doesn’t close properly. When this happens, the contents of your stomach — including food, drinks and stomach acid — flow back into your esophagus. You may experience a burning sensation in your chest known as heartburn.
Research into whether coffee causes reflux or worsens symptoms isn’t definitive. One study that examined coffee’s effects on the digestive system found that factors like obesity and other chronic health conditions cause reflux — not the beverage itself. But a different study found increased reflux symptoms after participants drank caffeinated coffee, tea or soda.
“Coffee and caffeine can increase the production of stomach acid,” DiMarino shares. “Coffee also relaxes the valve, allowing excess acid to enter your esophagus.” Both reactions can cause more severe and frequent reflux symptoms.
“Fat in milk sometimes aggravates reflux symptoms,” he says. “But low-fat dairy can act as a buffer between stomach acid and your stomach lining, which helps prevent heartburn.”
Ulcers are sores that form in your stomach or small intestine. They cause burning stomach pain, bloating and heartburn. While you might have heard that stress and diet (including coffee) cause peptic ulcer disease, research shows that’s not true.
The main cause of ulcers is Helicobacter pylori (H. pylori) infections, bacteria that eat away at your stomach’s protective lining and allow stomach acid to damage the tissue. The other top cause of ulcers is overusing nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and aspirin.
But coffee doesn’t appear to play a role. One study examined coffee consumption and ulcer formation in more than 8,000 people living in Japan. The study found no significant link, even among people who drank three or more cups each day.
Important to note, again, though: Although coffee may not cause stomach ulcers, it can increase how much stomach acid you make. If you already have an ulcer, higher amounts of stomach acid can make your symptoms worse.
Having coffee before you’ve eaten may not be bad for your health. But it could lead to a few unwanted side effects.
Your body absorbs coffee (and, therefore, caffeine) faster when there’s nothing else in your belly. This rapid absorption can intensify caffeine’s effects, making you feel anxious, jittery or irritable.
Caffeine can also raise blood pressure and cause your heart to feel like it’s beating too fast or skipping beats (heart palpitations). You may start experiencing these side effects within 10 minutes of having your first cup, although it typically takes up to an hour for caffeine’s full effects to kick in.
If you find yourself experiencing these effects after your morning cup, the fix is simple: Eat something along with your brew.
“Having food in your stomach slows the absorption of caffeine into your bloodstream,” DiMarino says.
He also recommends not adding sugar to your morning cup.
“Sugar causes a spike in blood sugar,” he says. The combination of sugar and caffeine can give you a quick burst of energy, followed by a crash that leaves you more tired than before. You might find yourself in a cycle of reaching for yet another cup of coffee with more sugar.
As many as 1 in 3 coffee drinkers report an urge to poop after enjoying a hot brew. This need to go number two can happen anywhere from four to 30 minutes after you set down your cup.
Research suggests that it’s the acids in coffee that make you poop. These acids stimulate hormone production — specifically, gastrin and cholecystokinin, which cause involuntary muscle contractions in your digestive system. That gets your bowels moving.
It’s not clear whether drinking coffee on an empty stomach will wake up your bowels faster. But findings suggest that caffeinated coffee is as effective as food, and 23% more effective than decaf coffee, at creating a laxative-type effect.
There really isn’t a “best time” to drink coffee, DiMarino says: “Everyone reacts to caffeine and coffee differently, so listen to your body.”
Some people have no issues drinking coffee on an empty stomach. But if you’re not one of them, DiMarino suggests making sure your breakfast has at least one of these: