Orange juice is a breakfast table staple—recent estimates suggest Americans drink about 486,000 metric tons of orange juice annually.
The beverage has a refreshing flavor, fast-acting sugars to boost energy, and ample vitamin C content.
But what happens when you down a full glass of orange juice first thing in the morning? You may wonder whether doing so could overwhelm your bloodstream with sugar, or whether the citrus’s acidity could cause stomach irritation, dental problems, or other issues.
According to experts and research, there can be both pros and cons to drinking orange juice on an empty stomach. Here’s what you need to know.
It Provides Quick Energy (Especially Before a Workout)
An 8-ounce glass of orange juice provides nearly 29 grams (g) of carbohydrates, 21 of which come from sugar.
Sugar is a type of carbohydrate, which are the body’s preferred source of energy. That means drinking orange juice by itself could give you a quick pick-me-up in the morning.
This is especially true because orange juice has very minimal amounts of fiber, which would otherwise slow down the body’s absorption of sugar.
According to Toby Amidor, MS, RD, a registered dietitian and cookbook author, this hit of energy can be helpful if you’re headed for an A.M. workout.
“OJ is a good pre-workout snack as it is easily digestible, which is what you want pre-workout— especially within 30 minutes of the activity,” Amidor told Health.
Essentially, the carbs in orange juice can replace glycogen (energy) stores and restock fluids that your body may have lost overnight, setting you up for a better workout.
Nutrients and Antioxidants Are Still Absorbed By the Body
When you drink your orange juice without food, there’s nothing to inhibit or compete with your body’s absorption of its nutrients—that goes for carbs, antioxidants, and vitamin C.
“A cup of freshly squeezed orange juice can contain over 100% of the recommended daily vitamin C intake for adults,” said Jennifer Phan, MD, gastroenterologist with Hoag Physician Partners in Irvine, CA.
That’s a good thing for your immune system—vitamin C helps protect existing immune cells and promote the production of new ones, Amidor said.
“The stomach does not need food present for vitamin C to be absorbed, so orange juice still delivers its antioxidant and immune-supporting benefits,” Phan told Health.
The same is true for other antioxidants in orange juice, including hesperidin, a phytonutrient which helps “protect the body’s cells against damage caused by free radicals,” Amidor explained. Hesperidin may also be good for heart health—research from 2021 found that hesperidin in orange juice improved the function of the endothelium, or the layer of cells that line the blood vessels.
Drinking orange juice solo won’t change anything, she said, so you’ll reap all of these benefits even on an empty stomach.
Despite the potential positives of drinking orange juice first thing in the morning, there’s a risk of some not-so-pleasant effects, too.
It Could Spike Blood Sugar
There’s a reason juices are often recommended as a quick treatment for low blood glucose (hypoglycemia): they rapidly raise blood sugar.
“The natural sugars in orange juice are absorbed quickly,” Phan explained. “Without food to slow the process, this can lead to a spike in blood sugar.”
Blood sugar spikes may sometimes lead to feelings of thirst, tiredness, headaches, blurred vision, or frequent urination. However, for most people, an increase in blood glucose isn’t too worrisome.
“The boost in natural sugar will give you a short spike, but it will go right back down,” Amidor said.
And even though drinking orange juice on an empty stomach may raise your blood sugar briefly, research suggests there’s no association between drinking 100% fruit juice and developing diabetes, she added.
“If you’re worried [about your blood sugar], then stick to one serving and consume with food or in a smoothie with other foods,” Amidor suggested.
You Might Experience Stomach Irritation
With a pH level of about 4, orange juice is certainly acidic. So for some people, drinking it by itself could cause gastrointestinal issues.
“On an empty stomach, there is no food to buffer its acidity,” said Phan. “This can lead to irritation of the stomach lining in people who are sensitive. It can also trigger heartburn and acid reflux.”
However, Phan noted that this is most common in people with underlying conditions, including gastroesophageal reflux disease (GERD), gastritis, ulcers, or irritable bowel syndrome (IBS).
Dental Enamel Could Take a Hit
The same acidity that could irritate your stomach could harm your tooth enamel, too.
“When you drink orange juice on an empty stomach, your body produces less saliva, which is what protects the teeth,” Michael Wei, DDS, founder of Manhattan Cosmetic Dentist, told Health.
When this happens, the acid from orange juice sits on the teeth, raising the risk of enamel erosion and tooth decay, he explained. A 2021 study found that, in the lab, commercially prepared grape, citrus fruit, strawberry, and orange juice increased the damage of tooth enamel and dentin (the material beneath the enamel).
To minimize these effects, Wei recommended drinking orange juice through a straw or following it up with a glass of water.
At the end of the day—or, rather, the beginning of the day—is it a good idea to drink orange juice on an empty stomach?
Having a glass of orange juice first thing in the morning is a solid way to boost energy, but Phan said drinking it with food is, in general, the better option.
By pairing your orange juice with a meal or snack, you’ll minimize any risks for dental erosion or stomach aches, keep your blood sugar more steady, and still reap antioxidant benefits.
