Prevent and Treat Kidney Stones Naturally

One of the most common diseases of our urological system worldwide is kidney stone disease (nephrolithiasis). One in ten individuals is expected to have a kidney stone once in their lifetime. About half a million individuals end up in the emergencies every year due to kidney stone discomfort or in order to remove large kidney stones. Since the 1970s, the prevalence of kidney stones has more than doubled in the U.S. All over the world, the incidence of kidney stone disease is growing and is equally high in both men and women¹.

The kidney stone formation depends on different factors. Some of them are related to diet, such as obesity, malabsorption of nutrients, consumption of vitamin C supplements of over 1,000mg per day and low calcium intake. However, other reasons many include genetics, or other health conditions such as diabetes, hyperparathyroidism and gout, certain medications, the composition of our gut microbiome or history of gastric bypass². Each of these factors can increase the concentration of certain elements or compounds in the urine, and crystals may begin to form². However, one of the most common and important risk variables for the formation and recurrence of kidney stone disease is diet³.

Types of kidney stones

Most of the kidney stones 70-80%) are made of calcium oxalate or calcium phosphate. The rest of them are of struvite (10%), uric acid (10%), and very few of cystine (<1%) or of several drug compounds. Calcium oxalate and uric acid stones are more common in males, whereas struvite stones are usually found in females. Here is a closer look of the different types of kidney stones³:

1. Calcium stones

Most of the calcium stones are formed of calcium oxalate (CaOx), calcium phosphate (CaP) or calcium urate. Oxalate is a product that your liver produces or that you consume through your diet. Some fruits, vegetables, nuts, as well as chocolate contain high oxalate. Other factors that can increase the concentration of calcium or oxalate in urine can be increased high doses of vitamin D, intestinal bypass surgery, and other metabolic disorders³.

Calcium phosphate stones are mostly formed due to metabolic conditions, such as renal tubular acidosis or because of certain medications that are used to treat migraines or seizures, such as topiramate³.

2. Uric acid stones

This type of stones may form in individuals who lose too many fluids due to chronic diarrhea or nutrient malabsorption. Other reasons may be a high protein diet, diabetes or metabolic syndrome. The risk of developing uric acid stones can also be increased by some genetic factors³.

3. Struvite stones

Struvite stones usually develop due to a urinary tract infection. This kind of stones, often with little signs, can grow rapidly and become very big³, creating pain and discomfort.

4. Cystine stones
These stones usually form in individuals with an inherited condition called cystinuria. During cystinuria, the kidneys excrete too much of a particular amino acid, called cystine³.

Kidney stones’ symptoms

Other than hematuria, kidney stones that are not blocking urination or the proper function of the kidneys do not create any symptoms. However, as they move through the ureter, they may cause extreme pain, generally followed by nausea, vomiting, and hematuria, accompanied by renal colic. Some people with such symptoms often feel a continuous need of urinating. The good news is that after passing the stone, symptoms improve fast.

Foods and drinks that cause kidney stones

1. Soft drinks

In the general population, especially in the USA, carbonated soft drinks (sodas) with added sugar are becoming more and more popular. On average, they contain 150 calories per 350 mL and they often have also added fructose. Fructose has the ability to increase the excretion of calcium, oxalate, and uric acid and has been associated with an increased risk of kidney stone disease⁶.

According to a scientific study, drinking 2 or more carbonated drinks per day increases significantly the risk of kidney stone formation. As stated also in a recent review²⁷ of the scientific literature from the last 20 years, cranberry juice tends to increase the concentration of calcium oxalate in the urine. So, it is better to avoid cranberry juice if you have a history of kidney stone formation.

2. High oxalate foods

As mentioned above, dietary oxalate is one of the most common reasons for the production of kidney stones. Oxalate is found primarily in plants that use it to extract the excess calcium present in the water. It actually accumulates in leaves, fruits, and seeds. Some vegetables like spinach, purslane, huanzontle (Chenopodium nuttalliae), beets, green cabbage, chard, amaranth and rhubarb contain large amounts of oxalate and may increase the increase the probability of developing calcium oxalate stones^{3, 7}.

Black tea has also higher concentration of oxalate comparing to oolong or green tea.

Almonds, beans, especially soybeans and chocolate are also high oxalate foods.

3. Salt

We all know that consuming a lot of salt may increase our blood pressure and affect the good function of our heart. However, it can also affect our kidneys, as high salt consumption makes our kidneys excrete more calcium and this may lead to kidney stone formation. Surprisingly, a 6g rise in daily dietary salt is capable of increasing the excretion^{8, 9}.

4. High animal protein diet

Apart from the fact that high meat consumption can increase the risk of cancer and cardiovascular disease, it can also increase the risk of formation of uric acid stones. This happens due to the high protein intake. Scientific studies have shown that if we consume a lot of non-dairy protein daily, mainly from fish, meat, poultry and eggs, our urine gets acidic which may also lead to the formation of calcium oxalate stones. Interestingly, the combination of high non-dairy protein with low-alcali foods (such as carrots, cauliflower, leeks, olive oil etc) is also correlated with high prevalence of urinary tract stones^{3, 11}.

5. Diet rich in carbohydrates

Some scientific studies have related the increased consumption of carbohydrates to the development of kidney stones. However, the effects of low carbohydrate diets on kidney stone disease have not been studied extensively and their results are partially conflicting. According to the scientific results, it looks like low-carbohydrate diets are protective against kidney stones, but more research is needed. Consequently, limiting mildly your carbohydrate intake and maintaining a good consumption of n-3 fatty acids seems the reasonable way to prevent kidney stones¹².

Useful habits to prevent kidney stones

• Drink enough water

Drinking enough water (>2L/day) is very important for the good function of our body. According to science, drinking more than the recommended daily amount of water is not going to help you prevent kidney stone formation^{13, 14}. However, if you have kidney stones drinking enough water in order to produce more than 2.5l of urine daily is going to help you pass the kidney stones faster.

• Check your water composition

Either if you drink tap water or bottled water it is not unusual to consume a lot of sodium (Na) together with it. Depending on the source of the water, mineral water can have high content of sodium, potassium, sulfates or other minerals. So, even if you take care of your salt consumption, consuming a lot of sodium together with your water may be a possible cause of kidney stone creation. To date, a water drinking standard for sodium content has not been set from the World Health Organisation (WHO) or any other health source. However, sodium content up to 20mg/l is recommended for people following sodium restricted diets (between 500mg – 2000mg/day) and up to 270mg/l for people who moderately restrict their sodium intake. Furthermore, according to a scientific study the intake of water with medium mineral (calcium 119.7 mg/l) and high bicarbonate (412 mg/l) content can change your urine composition and help you prevent stone formation.

• Follow a plant based diet
According to recent scientific data, high consumption of meat and low calcium (Ca) diets are directly associated with kidney stone formation. On the contrary, a balanced vegetarian or DASH diet with low fat dairy products is ideal to prevent kidney stone formation. As mentioned in many scientific studies, grapefruit, apple and orange juices are very effective in reducing the CaOx content in urine²⁷. It has even been scientifically proven that consuming high amounts of fruits and vegetables in addition to low-fat dairy products is capable of lowering the risk of stone events by up to a 45%¹⁰. It is important to know that luck of antioxidants (especially alpha-carotene, beta-carotene and beta-cryptoxanthin) have been associated with kidney stone formation¹⁵. Finally, high intake of vitamin E and phytate through your diet can also help you prevent kidney stone formation¹².

Introduce more vegetables, fruits, soups, nuts and low fat dairy products like yoghurt and whole grains in your diet and avoid eating too many almonds, chocolate and beans. In that way, you will prevent kidney stone disease and achieve a balanced diet and a good overall health.

• Cook your vegetables well

Chopping and cooking your vegetables well reduces the amount of oxalate in them and thus in your diet.

• Watch your calcium (Ca) intake

Consume sufficient calcium (1,000 – 1,200 mg/ day) through your diet is enough to help you prevent kidney stone formation. However, calcium supplements can have exactly the opposite effect and may increase the risk of kidney stone creation16. Drinking milk or drinks containing calcium (fortified beverages and foods) together with your meals can also help to decrease the absorption of oxalate.

• Reduce your salt intake

As mentioned above, high sodium (Na) intake can increase dramatically the excretion of Ca in your urine and thus the risk of forming calcium oxalate stones. So, taking care of your salt intake and limiting it to the recommended 2,000 to 2,300 mg/day (1tsp.) is very helpful to prevent kidney stones.

• Limit your vitamin C intake

Consuming too much of vitamin C (> 1,000 mg/day), either through your diet or by taking supplements, has been directly associated to kidney stone formation3. Thus, although vitamin C is essential for a good health and a strong immune system it would be better to control how much you consume.

Natural prevention of kidney stones

1. Green tea

3. Pomegranate

Pomegranate (Punica granatum) has so many health benefits that it is known as a “a pharmacy unto itself”19. It can be of help not only for preventing kidney stone formation, but also for facilitating their removal. Drinking pomegranate juice has been shown that it helps to regulate urea, creatinine, and ureic acid in your body. In a scientific study, people (18–70 years old) who had calcium based stones before were given pomegranate extract for 90 days. The results showed that the chance of forming new stones again was reduced as the saturation of calcium oxalate was also significantly decreased.

4. Solanum xanthocarpum

Solanum xanthocarpum, also known as “yellow-fruit nightshade” and “Thai green eggplant”, is an edible plant in India that is traditionally used for treatment of kidney related diseases. According to several scientific studies it can be effective when someone is suffering from difficulty in urination, urinary infections, nephrotoxicity and kidney stone disease. The fruits of these plants contain some molecules, called saponins, which are great for preventing kidney stone formation¹⁹.

5. Urtica dioica

Urtica dioica or “Stinging Nettle” is used as a tea in Austrian medicine and has been used as a traditional natural remedy for kidney stones. Although it has not been studied well scientifically, there is one study in rats that showed it effectiveness against the formation of kidney stones. According to the results of this study the methanolic extract of this plant can prevent the formation of kidney stones, but it can also dissolve them and facilitate their passing.

6. Origanum vulgare

Oregano contains so many phytochemicals and it has been used since the ancient times as a medicine for several diseases. Among the other health benefits that O. vulgare has, it is helpful for breaking kidney stones, it increases urination frequency in order to get rid of them faster and it also prevents spasms. Finally, oregano can also help you prevent calcium oxalate aggregation and precipitation, so as new stones are not formed²⁵.

7. Vinegar

There is one scientific study where the researchers tested the effect of Ninghuafu® vinegar on kidney stone prevention. They showed that vinegar, due to its acetate content could prevent the formation of calcium oxalate stones by influencing urinary citrate and calcium excretion via epigenetic regulations. So, you could try to consume 3 table spoons of vinegar daily, either grape vinegar or apple cider vinegar, in order to prevent CaOx stone formation.

8. Hibiscus sabdariffa

Tea of this plant has been traditionally used in Thai medicine as a natural treatment against kidney stones. The phytochemicals contained in the seeds have been shown to prevent the formation of calcium oxalate crystals and thus CaOx stones¹⁹. According to a clinical trial, drinking tea prepared with 1.5g of Hibiscus sabdariffa for 15 days, is enough to prevent CaOx stone formation.

How to treat kidney stones naturally

1. Raspberries

The potential of raspberry juice for removing kidney stones has been tested in several scientific studies. It seems that raspberries (Rubusidaeus, Rosaceae family) have great diuretic activity and can help you stop the growth of kidney stones and get rid of them faster¹⁹.

2. Pomegranate
This fruit is ideal to help you flash kidney stones more easily. It relaxes your urinary and biliary tract as well as soothes the burning sensation while urinating²³.

3. Pistacia lentiscus

Although Pistacia lentiscus (Anacardiacceae) or Mastihodendro in Greek, is commonly used for its’ gum, its’ fruit extract is also very beneficial for the kidney stones. It actually protects the kidney cells from being damaged from several toxic compounds produced in the kidney while someone has kidney stones²⁴.

4. Nigella sativa – Black cumin

The seeds of this plant are traditionally used in the Iranian medicine for the treatment and prevention of kidney stones. The extract of black cumin seeds can reduce the concentration of calcium oxalate in urine. According to one scientific study in rats, it can also decrease the size and the number of calcium oxalate stones²⁶.

5. Ammi visnaga

If you are suffering from cystine stones, Amni visnaga or Khella is the plant that can help you. It has been traditionally used in Egypt as a medicinal plant and it has been shown to be effective in breaking cystine type stones as well as to reduce the pain induced from them. You can drink Khella as tea. In order to prepare the tea, you simply pour boiled water in 30-300mg of its fruit powder, leave it for 10-15min and then strain it²⁸. There is also one study in rats²⁹ which showed that Khella can also be efficient for the prevention of CaOx stones, but further research is needed.

When to see a doctor

Seek immediate medical attention if you experience the following symptoms⁴:

• Pain so intense that you cannot sit still or find a comfortable position
• Pain followed by nausea and vomiting
• Pain followed by fever and chills
• Blood in your urine
• Difficulty with urine passing

Take home message

Normally, stone formation in normal kidneys is relatively rare and is probably due to a combination of factors, such urinary acidity, dietary habits, several health conditions or even regular intake of calcium supplements (calcium oxalate, calcium citrate, and calcium carbonates). Kidney stones can be avoided by a balanced diet (unless there is a medical, genetic, or other non-dietary cause). If your family has a history of kidney stone formation it would be useful to include some of the above plants in your diet, as well as follow a balanced diet. Keep in mind that depending on the type of stones you need to use the respective plant for their prevention or treatment.

References

1. Konjengbam H, Meitei SY, Association of kidney stone disease with dietary factors: A review. Anthropol. Rev. 2020; 83, 65–73.
2. Frassetto L, Kohlstadt I. Treatment and prevention of kidney stones: an update. Am Fam Physician. 2011 Dec 1;84(11):1234-42.
3. Ferraro PM, Bargagli M, Trinchieri A, Gambaro G, Risk of Kidney Stones: Influence of Dietary Factors, Dietary Patterns, and Vegetarian–Vegan Diets. Nutrients 2020, 12, 779.
4. Han H, Segal AM, Seifter JL, Dwyer JT. Nutritional Management of Kidney Stones (Nephrolithiasis). Clin Nutr Res. 2015; 4(3):137-152.
5. Stanford J, Charlton K, Stefoska-Needham A, Ibrahim R, Lambert K, The gut microbiota profile of adults with kidney disease and kidney stones: A systematic review of the literature. BMC Nephrol. 21, (2020).
6. Fox IH, Kelley WN, Studies on the mechanism of fructose-induced hyperuricemia in man. Metabolism. 1972; 21:713–721.