Can Drinking Too Much Grapefruit Juice Be Harmful?

Grapefruit is a hybrid of the orange and pummelo, which is basically a larger version of the grapefruit. The fruit and its juice are rich in nutrients, including pectin fiber, vitamin C and other antioxidants such as flavonoids. While grapefruit juice is nutritious, it can also be harmful in small or large doses.

Grapefruit juice can help you lose weight and reduce your risk of type 2 diabetes, according to a study in the "Journal of Medicinal Food" conducted by the Department of Nutrition and Metabolic Research at Scripps Clinic in California. However, you can have too much of a good thing. Weight gain is the result of consuming too many calories and not getting enough exercise. Plus, if you drink sweetened grapefruit juice, keep in mind that sugar-sweetened drinks are leading contributors to obesity.

One of the well-known dangers of grapefruit juice is its ability to interact with numerous medications, even in small amounts. It can make drugs too potent or reduce their effectiveness. For instance, you should not drink grapefruit juice if you're taking kidney disease medications, antihistamines, antibiotics or medications to lower cholesterol without consulting your doctor. Other drugs grapefruit juice might affect include immune suppressants and some heart disease medications such as calcium channel blockers.

Gastroesophageal reflux, or heartburn, occurs when the lower esophageal sphincter between the stomach and esophagus is weak or doesn't function properly. As a result, it allows acid to flow back up from the stomach into the esophagus. Citrus juices such as grapefruit juice can weaken the lower esophageal sphincter, contributing to heartburn and symptoms such as burning, chest pain and a bitter taste at the back of your mouth.

Too much grapefruit juice can also be harmful to your teeth. In a study published in the "Journal of Dentistry" in 2005, researchers from Thailand and the U.S. found that acidic drinks erode and soften tooth enamel. The lower the pH of a particular food, the greater its erosive effects.Neutral pH is 7.0; grapefruit's is between 2.90 and 3.25. Loss of tooth enamel begins at 5.5 pH. Whenever possible, drink grapefruit juice through a straw to protect your teeth.