Kidney stones can be an incredibly painful and uncomfortable condition. Many people seek ways to prevent their recurrence. Interestingly, orange juice has emerged as a potential dietary intervention. A daily glass of orange juice may be more effective than other citrus fruit juices, such as lemonade, in preventing kidney stone recurrence. While it’s often assumed that all citrus fruit juices help prevent the formation of kidney stones, research indicates that they don’t all have the same effect.
The Role of Citrate
Orange juice can increase citrate levels in the urine. It also reduces the crystallization of uric acid and calcium oxalate. Citrate, a negatively charged form of citric acid that gives citrus fruits their sour taste, binds to calcium in the urine, which prevents the formation of stones.
In a study conducted at the University of Texas Southwestern Medical Center in Dallas, researchers found that orange juice consumption boosted citrate levels in the urine. Lemonade, however, didn’t increase citrate levels.
The Study
In the UT Southwestern study, 13 volunteers participated in three phases, each lasting one week. The phases, chosen in random order, included a distilled water control phase, an orange juice phase, and a lemonade phase. There was a three-week interval between each phase.
During each phase, volunteers drank 13 ounces of orange juice, lemonade, or distilled water three times a day with meals. They also followed a low-calcium, low-oxalate diet. Urine and blood samples were taken at intervals during each phase. The study was conducted at UT Southwestern’s General Clinical Research Center.
The study revealed that orange juice increased citrate levels in the urine and reduced the crystallization of uric acid and calcium oxalate, the most common components of kidney stones. Conversely, lemonade did not increase citrate levels.
Potassium Citrate
Orange juice has a high level of potassium citrate. Potassium citrate binds to calcium in the urine, preventing stones from forming. Orange juice delivers an equivalent alkali load and causes a similar increase in urinary pH and urinary citrate compared to potassium citrate.
Orange Juice vs. Lemonade
Although many people think that all citrus fruit juices can help prevent kidney stones, research suggests that not all citrus juices have the same effect. While both orange juice and lemonade contain comparable levels of citrate, the components that accompany the citrate can alter the effectiveness of the juice in reducing the risk of developing new kidney stones. Orange juice has greater alkalinizing and citraturic effects than lemonade and is associated with lower calcium-oxalate supersaturation and lower uric acid.
Other Considerations
While orange juice seems to have a protective role against stone formation, it is important to consider its high sugar content. Also, orange juice and grapefruit juice significantly increased urinary oxalate levels.
Dietary Fiber
A high intake of dietary fiber from fruits and vegetables is associated with a reduced risk of kidney stones. The fiber content in citrus fruits may also contribute to their protective effect.
Conclusion
Consuming orange juice may help prevent kidney stones. Orange juice increases levels of citrate in the urine and reduces the crystallization of uric acid and calcium oxalate. Orange juice has a high level of potassium citrate, which binds to calcium in the urine, preventing stones from forming.