People with hypocitraturic nephrolithiasis (low citrate urinary stones) benefit by drinking more citrates, either in orange or in lemon juice. Potassium citrate tablets have been standard therapy for urinary stones. Potassium citrate therapy results in reduced stone formation. This study is of the relative benefits of commercially available citrus drinks which are available.

Citrate can complex with calcium, reducing the crystallization of calcium in supersaturated urine. Citrate can convert to bicarbonate, releasing an alkali load to the urine, increasing the pH, and increasing the solubility of stoneforming urine components.

Grapefruit juice, orange juice, and lemon juice, cranberry juice, and pineapple juice were the natural juices tested. The artificial products tested were reconstituted lemonade, lemonade flavored Crystal Light, lemon-flavored Gatorade, Mountain Dew, Diet 7Up, and homemade lemonade.

The highest amount of citrates was found in grapefruit juice, followed by lemon juice, orange juice, pineapple juice, and reconstituted lemonade. The lowest levels of citrates were seen in Mountain Dew, and Diet 7Up.

The problem with using grapefruit juice as routine therapy is fact that grapefruit interferes with the p450 enzymes, resulting in high blood levels of drugs which depend on p450 for metabolism. This includes a number of cardiac drugs. Grapefruit juice is not considered an ideal treatment of nephrolithiasis for this reason. Grapefruit is a good treatment for low citric acid levels in people who are not on medications with metabolism altered by p450.

The negative side of orange juice and lemon juice use is that they contain calories, about 100 calories per glass. On the other hand, they do contribute to the potassium intake.

The suggested potassium citrate dose is 40-60 mEq/d. The amount of Ruby grapefruit juice needed to supply 40 mEq is 202.52 ml. If you take Crystal Light the same dose you would have to drink 341.36 ml and you would receive almost no calories.

CONCLUSION: People with low citrate levels and urinary stones are treated with potassium citrate. Citrates raise the urinary pH and reduce the tendency of small crystals to aggregate

If commercial beverages are used for functional foods, grapefruit juice is best for people who are not on medications and are not concerned about calories. People who are on medications, especially certain heart drugs, should consider orange juice or lemon juice. People who are concerned about calories should consider lemonade-flavored Crystal Light.

NOTE: Cytochrome 450 is a super family of enzymes which can alter the metabolism of medications. Check the pharmacy information of drugs you take to see if grapefruit juice interferes with the metabolism of your drugs.

You can test the pH of your urine with pH paper.

PMID: 18578663.

Summary #470.