Natural ways to prevent kidney stones

My dad is prone to kidney stones (calcium oxalate stones) and is looking for natural ways to prevent them. Fortunately, so far, his stones have been small and he’s not required surgery, but he’s worried he may not be so lucky next time. Can you recommend any holistic solutions?

S.P., via email

Kidney stones—when hard deposits of minerals and salts form inside the kidneys—are a common disease of the urinary tract.1 Usually made of calcium oxalate, the stones can cause symptoms when they move around in the kidney or pass into the ureters—the tubes that carry urine to the bladder. If a stone lodges in the ureters, it can block urine flow and lead to severe pain, nausea, fever and pink or brown urine.

If you have small stones, you’ll probably be advised to drink plenty of water, use painkillers and possibly take an alpha blocker, a drug to ease the passage of stones with side-effects including dizziness, low blood pressure and sexual dysfunction.2 

Larger stones may require techniques such as extracorporeal shock wave lithotripsy (ESWL; using sound waves to break up the stones) or percutaneous nephrolithotomy (PCNL; surgically removing stones using a thin telescopic instrument). But these, of course, come with risks, including kidney damage, and don’t stop stones from recurring.3

Preventative medication, such as thiazide diuretics, is sometimes prescribed to those prone to kidney stones. But the drugs are not particularly effective and come with a high rate of adverse reactions.4

The good news is there are plenty of simple diet and lifestyle changes that can help prevent kidney stones, as well as useful herbs and supplements. Your dad will be best off seeing a qualified naturopathic practitioner who can come up with a personalized treatment plan, but here are some general recommendations for calcium oxalate stones that you can pass on to him.

Stay hydrated

Drinking plenty of fluids, especially water, is important to prevent kidney stones. It helps to dilute the substances in urine that form the stones. In one study, each 500 mL (17 oz) increase in water intake was associated with a significantly reduced risk of kidney stone formation.5
Adding some lemon juice to your water may bring extra benefits, as lemons are high in stone-preventing citrate. One long-term trial reported that drinking 120 mL of concentrated lemon juice mixed with 2 liters of water throughout the day reduced stone formation.6
Drinks to avoid, on the other hand, are sugary sodas such as cola.7

Eat more fruit and veg

Eating plenty of fruit and vegetables can help protect against kidney stones. In particular those rich in citrate, such as citrus fruits, and high in potassium, such as bananas, melon and avocado, may reduce stone formation.8 Avoid fruit and vegetables high in oxalate, though, as eating them could actually increase your risk for kidney stones.9

Limit oxalate

Found naturally in many foods, oxalate intake has been linked to kidney stones. In one study, people who consumed the most dietary oxalate were up to 20 percent more likely to develop kidney stones than people who ate the least.10 The main foods to watch out for seem to be spinach, rhubarb, beets, nuts, chocolate, tea, wheat bran and strawberries.11

It’s also important to get enough calcium in your diet, as it binds to oxalate in the gut, reducing the amount of oxalate absorbed by the body.12 In fact, one small study found that high oxalate intake did not increase the risk of kidney stones as long as participants were meeting the daily recommended intake for calcium.13

Foods rich in calcium include sardines, salmon, dairy products, chia seeds, sunflower seeds and figs. Aim to consume about 1,000–1,200 mg calcium per day.14

Sidestep salt and sugar

High dietary salt intake can increase the risk of kidney stones.15 And sugar appears to increase urinary stone formation via its effects on urinary pH and oxalate.16 Try to avoid refined sugar like table sugar and high fructose corn syrup, and limit salt. Cutting out processed foods will help, as these often contain large amounts of added salt and sugar.

Get moving

A large study in women suggests being physically active can reduce the risk of kidney stones by up to 30 percent.17 But another study found no association.18 Still, being active is good for health overall and can help to maintain a healthy weight, which appears to be important for kidney stone prevention. Just remember to stay hydrated when you exercise. Sweating can lead to less urine production, which can encourage stone formation.

Eat pumpkin seeds

Pumpkin seeds are an excellent source of calcium, potassium and magnesium, all of which appear to play a role in preventing kidney stone formation. And two trials in Thailand found that eating the seeds can reduce the urinary risk factors for developing kidney stones.19

Supplement

Certain supplements seem to be helpful for reducing the formation of kidney stones. Be sure to consult with a qualified practitioner, who can recommend appropriate dosages for you as an individual. 

Potassium-magnesium citrate. A three-year study found that supplementing with potassium-magnesium citrate can reduce the recurrence of kidney stones by 85 percent.20

Suggested dosage: 1,600 mg/day potassium citrate and 500 mg/day magnesium citrate 

IP-6 (inositol hexaphosphate or phytic acid) can reduce the formation of calcium oxalate crystals in the urine of people prone to kidney stones.21 The supplement is widely available online.

Suggested dosage: follow the label instructions

Vitamin E. Some evidence suggests that vitamin E might be beneficial for preventing kidney stones.22

Suggested dosage: 200 mg/day

Vitamin B6 and magnesium. Supplementing with a combination of these nutrients may help stop kidney stones from recurring.23

Suggested dosage: 200–300 mg/day magnesium oxide, 10 mg/day vitamin B6

Check your meds

Certain drugs have been linked to kidney stones, such as loop diuretics, sulfasalazine and topiramate, so check with your doctor about any you’re taking.24

Hydrating herbal tea

Herbalist Meilyr James recommends drinking this herbal tea to encourage hydration of the body.

Add 1 heaped teaspoon of the following herbs for every 300 mL boiling water and allow to infuse for 20 minutes. Drink three times daily.

Use equal parts of:

Zea mays (corn silk), a soothing diuretic herb with gentle antilithic action.

Equisetum arvense (horsetail), which promotes kidney function and toning the walls of the urinary system.

Solidago virgaurea (goldenrod), which reduces inflammation and heals the lining of the kidneys.

Top tip: When passing small stones, take a hot bath while drinking 2–3 pints of liquid, alternating between herbal tea and warm water to help flush them through.

Get help from herbs

According to herbalist Meilyr James, owner of the Herbal Clinic in Swansea, Wales
(www.herbalclinic-swansea.co.uk), the formation of kidney stones indicates that elimination from the kidneys is insufficient. The herbal medicine solution is ‘antilithic’ herbs, which help to dissolve small kidney stones and prevent the formation of new ones. The following recipe can be used for these purposes. For larger stones, it’s important to consult with a qualified health practitioner, says James. 

Use tinctures of the following herbs combined in equal parts. Take 5 mL, three times daily in a little water.

Parietaria officinalis (pellitory-of-the-wall), 1:5 tincture. In addition to its antilithic action this herb has a restorative effect on the kidneys, supporting and strengthening their function, says James.

Hydrangea arborescens (wild hydrangea), 1:3 tincture. Hydrangea has a diuretic effect, encouraging the flow of urine and the passing of stones.

Viburnum opulus (cramp bark), 1:3 tincture. As the name suggests, this herb is useful for cramping pain, relaxing smooth muscle tension and thereby easing some of the discomfort of kidney stones and the passing of small pieces of stone.

Consider cadmium

Occupational exposure to cadmium has been linked to kidney stones,25 so consider whether you may be exposed to this toxic heavy metal on the job. Dietary exposure to cadmium in the general population, however, was not found to increase the risk.26

Tobacco is a source of cadmium, so if you’re a smoker, this is another reason to quit. In fact, smoking may be an independent risk factor for kidney stones.27

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