NMU 255 – Diet to Prevent Kidney Stones and Their Recurrence

Nutrition/Natural Medicine Update No 255 (August 24, 2022)

with Dr. James Meschino

Topic: Diet to Prevent Kidney Stones and Their Recurrence

Source: Mayo Clinic Proceedings (August 1, 2022)

What is the right diet to prevent kidney stones and to prevent the recurrence of kidney stones? These are important questions because in 30% of cases people who have had one kidney stone will have a recurrence. I’m sure you are aware of how painful a kidney stone can be. According to the 2018 report in the journal Advances in Urology, kidney stones are an increasing urological disorder of human health, affecting 12% of the World’s population and is associated with an increased risk of end-stage renal (kidney) failure.  Although the cause of kidney stones can involve many factors, with calcium oxalate stones being the predominant type of kidney stone, the 2022 review by Mayo Clinic researchers has shed light on what should be considered the most prudent dietary pattern to prevent kidney stones and their recurrence. They arrived at these recommendations by using data from questionnaires completed by kidney stone patients between 2009 and 2018. They compared the diets of 411 people who had already had their first kidney stone and a control group of 384 individuals (who had no history or evidence of kidney stones). During an average follow-up period of just over four years, 73 patients in the study had recurrent kidney stones.

The key finding was that a low intake of calcium and potassium increased the risk of recurring stone formation to a significant degree. This is contrary to what many health experts have said in the past, that too much calcium intake, including calcium supplements, causes kidney stones. But that appears to be incorrect according to the data we have available at this time. Not enough calcium intake is actually shown to increase the risk of kidney stone development.  In fact, the researchers recommend ingesting 1200 mg per day of calcium to prevent kidney stones, which happens to also be within the range that reduces the risk of osteoporosis. They suggest that you get as much of it as possible from healthy food, like non-fat or 1% yogurt. But ingesting 1200 mg per day should be the target and in many cases that may require getting 500 mg or more from a dietary supplement.

As for acquiring sufficient potassium, they had a hard time nailing down a specific number, but health authorities recommend about 3500-4700 mg per day, which you can easily acquire from potassium-rich fruits and vegetables, such as bananas, oranges, grapefruits, apricots, mushrooms, peas, cucumbers, zucchini, and melons such as cantaloupe and honeydew. Fruits and vegetables contain other nutrients that may also reduce the risk of kidney stones, according to the Mayo Clinic research team. They also showed that fluid intake below 3,400 ml per day (about nine, 12 oz glasses of fluids) is associated with first-time stone formation. But some of your fluid intake can also come from water-rich foods like fruits and vegetables. As well, caffeine intake can help to prevent kidney stones by creating a diuretic effect, thus diluting minerals in the urine so they are less inclined to bond with oxalic acid and form a stone. But surprisingly low calcium and potassium intake were a stronger predictor of kidney stone development than low fluid intake in the Mayo Clinic Database study.

The bottom line is that one of your wellness objectives should be to avoid kidney stones or their recurrence. The evidence I am citing today indicates that paying attention to adequate calcium intake, getting ample amount of a wide variety of fruits and vegetables in your diet (to acquire potassium), ensuring adequate fluid intake, including some caffeinated beverages if you like, such as coffee and tea, are key strategies to help ward off kidney stone development.

I have included the references for this information in the text below.

References:

1. Alelign T and Petros B. Kidney stone disease: An update on current concepts. Adv Urol. 2018: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5817324/#:~:text=It%20is%20an%20increasing%20urological,of%20kidney%20stone%20is%20multifactorial.

2. John Lieske, MD, director, O’Brien Urology Research Center and consultant, division of nephrology & hypertension, department of internal medicine, Mayo Clinic, Rochester, Minn.; Gary Curhan, MD, professor, Harvard Medical School and member, Channing Laboratory and Renal Division, Brigham and Women’s Hospital, Boston; Mayo Clinic Proceedings, Aug. 1, 2022, online https://consumer.healthday.com/8-2-had-a-kidney-stone-this-diet-may-help-prevent-another-2657772530/was-this-page-helpful

3. Diets higher in calcium and potassium may help prevent recurrent symptomatic kidney stones. Science Daily August 1, 2022 https://www.sciencedaily.com/releases/2022/08/220801102923.htm

Eat Smart, Live Well, Look Great,

Dr. Meschino