Role of Citrus Fruit Juices in Prevention of Kidney Stone Disease (KSD): A Narrative Review

Abstract

To explore the relationship between citrus fruit juices (oranges, grapefruits, and lemonades) and kidney stone disease (KSD). Methods: A systematic review was performed using the Medline, EMBASE, and Scopus databases, in concordance with the PRISMA checklist for all English, French, and Spanish language studies regarding the consumption of citrus fruit juices and the relationship to urinary stone disease. The main outcome of interest was the association of citrus fruit juices with KSD. Results: Thirteen articles met the criteria for inclusion in the final review. Three large epidemiological studies found that grapefruit juice was a risk factor for stone formation, while orange juice did not increase the risk for KSD. Ten small prospective clinical studies found that orange, grapefruit, and lemon juices all increased urinary citrate levels. Only orange and grapefruit juices had an alkalinizing effect and while lemon juice has a protective effect by raising urinary citrate levels, it lacked a significant alkalinizing effect on urine pH. Orange juice and grapefruit juices significantly increased urinary oxalate levels, while orange juice also had a high carbohydrate content. Conclusion: While orange juice seems to play a protective role against stone formation, grapefruit was found to raise the risk of KSD in epidemiological studies but had a protective role in smaller clinical studies. Lemon juice had a smaller protective role than orange juice. Larger amounts of, as well as more accurate, data is needed before recommendations can be made and a high carbohydrate content in these juices needs to be taken into consideration.

Effects of lemon–tomato juice consumption on crystal formation in the urine of patients with calcium oxalate stones: A randomized crossover clinical trial

“…This finding implies that the tendency for crystal formation in patients treated for CaOx stones can significantly decrease if lemon–tomato juice is added to the diet as a source of citrate. This is consistent with the report by Barghouthy and Somani that in the urine, citrate from citrus and noncitrus fruit juices inhibits the spontaneous nucleation and agglomeration of CaOx crystals [13] ; however, such finding is in contrast to that of Ho et al that consumption of citrate-containing juices fails to reduce CaOx crystal formation. [14]…”

“…[16] An important but largely underestimated factor is the high sugar content of the juice consumed; lemon juice is usually consumed with added sugar or salt, both of which are established risk factors for urolithiasis. [13,17] Hence, lemon juice should be consumed without added salt or sugar, but this makes it unpalatable and may be associated with gastrointestinal disturbances in many patients. Such recommendation can contribute to decreased patient adherence to long-term lemon juice supplementation.…”

“…[18] This may explain the fact that many studies do not show the expected clear protective role of lemon juice against stone formation. [13,19] The high citrate and magnesium contents and the low sodium and oxalate contents of tomato juice have been established by various studies, making this juice an ideal candidate for the prevention of stone formation. However, poor patient compliance has been reported even with long-term tomato juice supplementation.…”

Impact of habitual intake of glucosamine, fresh fruit, and tea on the risk of urolithiasis: A two-sample Mendelian randomization study

“…Citrus varieties, namely lemons, limes, and oranges, stand as rich natural sources of citric acid. [50] Recorded meta-analytic evidence indicates that high citrus consumption correlates with elevated urinary pH and citrate concentrations in comparison to control subjects. [51] Furthermore, among individuals afflicted with urolithiasis, those consuming citrus fruits demonstrate a reduction in urinary calcium discharge.…”

Secondary oxalate nephropathy and kidney transplantation

“…Some epidemiological data shows that excessive use of grape juice can increase the risk of stone formation. On the other hand, lemon juice may have a beneficial effect on urinary chemistry to reduce the risk of stone formation [64,65]. Patients should be encouraged to avoid fad diets focused on 'juicing,' as these diets supply high dietary oxalate, and increased paracellular absorption of oxalate in the intestines can overwhelm renal excretion.…”