Kidney stones are hardened pieces of minerals that most commonly form when excess amounts of calcium and oxalate or phosphorus build up in your kidneys. These stones can cause a number of symptoms, including intense pain in your back and blood in your urine. Your hydration level and diet are the two most common contributors to kidney stones. One thing that can help to create an environment where kidney stones are less likely to form is to increase your intake of citrate -- found in high amounts in lemons.
Significance
The sour taste in lemons comes from a high concentration of citric acid, also called citrate. This substance gives citrus fruits part of their tangy flavor and can help to prevent kidney stones by binding with urinary calcium, which reduces the amount of calcium that can bind together to create or enlarge kidney stones. For this reason, potassium citrate is often prescribed to patients to prevent kidney stones. Although lemons may not be as potent as potassium citrate, they can have similar effects.
Types
Kidney stones are made of different substances. When you experience symptoms related to kidney stones, your physician may recommend a collection method such as using a paper funnel to "catch" kidney stones in your urine. These stones can then be sent to a laboratory for testing. Lemons have protective effects for stones that have calcium as a component. Calcium stones are the most common types of kidney stones and can also combine with oxalate or phosphate. However, other types of stones, such as struvite stones or cystine stones, will not respond to lemons as a treatment. However, increasing your fluid intake can benefit all types of kidney stones.
Citrate Content
In terms of grams per ounce, lemons have the highest amount of citric acid of the citrus fruits, including lemons, limes, grapefruits and oranges, according to a study published in the "Journal of Endourology." Lemon juice squeezed from the fruit itself has about 1.44 g per ounce of citric acid while orange juice has about 0.50 g/oz. Although you likely will not drink fresh-squeezed lemon juice by itself thanks to its mouth-puckering, sour taste, its high citric acid content is why experts quoted on the website of "The New York Times" recommend using fresh-squeezed or concentrated lemon juice when preparing your anti-kidney stones lemon drink.
Daily Intake
To reduce the formation of calcium-based kidney stones, "The New York Times" recommends adding one-half cup of pure lemon juice to about 64 oz. of water and drinking this mixture throughout the day. You can purchase a large container and serve portions from the container each day. Drinking this volume of water combined with the lemon juice has been shown to raise citrate to protective levels.
References
- CBS News; Lemonade Vs. Kidney Stones; Christine Lagorio; February 2009
- "The New York Times"; Kidney Stones; July 2009
- University of California, San Diego, Health System; Five Ways to Prevent Kidney Stones: From Lemonade to Surgery; April 2010
- "Journal of Endourology"; Quantitative Assessment of Citric Acid in Lemon Juice, Lime Juice and Commercially Available Fruit Juice Products; Dr. Kristina Penniston, et al.; March 2008
