Low in calories and high in fiber and essential vitamins and minerals, grapefruits are a healthy addition to your diet. But if you find you get indigestion or an upset stomach after eating them, you may have to give them up. Citrus fruits such as grapefruit can trigger heartburn, and some people have a citrus intolerance or allergy. Speak to your doctor about whether grapefruit is causing your stomach discomfort and what you can do about it.
Your esophagus transports food from your mouth to your stomach for digestion. A muscular band around the lower esophagus, called the esophageal sphincter, allows food and liquid to pass through to the stomach but prevents stomach contents from flowing back into the esophagus. Certain foods and other factors such as smoking and being overweight can weaken the esophageal sphincter, allowing stomach acid to enter the esophagus. This results in a range of symptoms, including stomach discomfort. Grapefruit and other citrus fruits have a high acid content and can trigger or worsen acid reflux.
Grapefruits are high in salicylates, compounds found in plants used to protect the plants from diseases, insects, fungi and bacteria. For people with a salicylate sensitivity, eating grapefruit can cause a reaction. Symptoms of salicylate sensitivity include stomach pain, diarrhea and nausea. If a salicylate sensitivity is to blame for your gastrointestinal discomfort, you will likely also have discomfort after eating other fruits high in salicylate such as apples, cantaloupe, kiwi, melons, peaches, cranberries, grapes, currants and watermelon.
Citrus Intolerance and Allergy
Some people are allergic to citrus fruits, including grapefruit, although this is rare. A food allergy is an immune response to a protein found in certain foods. An intolerance, on the other hand, is not an immune response and will not show up in allergy testing. However, both an allergy and an intolerance to citrus can manifest in stomach problems, including abdominal pain, diarrhea, nausea and vomiting. In the case of an intolerance, you may be able to eat a small amount of grapefruit without symptoms; with an allergy, even a small amount will cause a reaction.
When to Avoid Grapefruit
If grapefruit triggers your acid reflux, Jackson Siegelbaum Gastroenterology recommends limiting or avoiding it. A citrus allergy may result in severe symptoms that can be life-threatening, including anaphylaxis and death, so it is important to see your doctor to determine whether you have an allergy. According to the Family Allergy & Asthma Care of Montana, for some people eating grapefruit within two hours of exercising can trigger food-dependent exercise-induced anaphylaxis.