Fact Check: Can fennel seeds, rock candy and coriander seeds dissolve kidney stones?

Claim: An Instagram post claims that a mix of fennel seeds (saunf), rock candy (mishri), and coriander (dhania) powder can help pass kidney stones. According to the user- dryusuf_malik, kidney stones measuring between 4 to 6 mm can be removed with this mixture. The preparation involves combining 50 grams each of fennel seeds, rock candy, and coriander seeds, grinding them into a powder, and taking this powder with a glass of water before bedtime. The user asserts that following this regimen for 10-12 days will dissolve and help pass the kidney stones. The video detailing this method can be accessed here.

Fact Check: This claim is False. 

What are kidney stones?

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), kidney stones are solid, pebble-like materials that can form in one or both of your kidneys when high levels of certain minerals are present in your urine. Kidney stones rarely cause permanent damage if treated by a healthcare professional.​ The symptoms include sharp pain in the back, side, lower abdomen, groin, or hematuria (blood in urine). A small stone can easily pass through the urinary tract, and there might be no symptoms. (1)

Types of Kidney Stones 

About Fennel Seeds (saunf), Coriander Seeds (dhaniya) and Rock Candy (mishri) 

Fennel seeds or saunf have various pharmacological effects, including anti-allergic, analgesic, anti-inflammatory, antioxidant, antibacterial, anti-cancer, anti-stress, and cytotoxicity activity. (2)

Coriander seeds or dhaniya provide protective effects against neurodegenerative diseases, cancer, and metabolic syndrome. Coriander also possesses certain antioxidant, anticancer, neuroprotective, anxiolytic, anticonvulsant, analgesic, migraine-relieving, hypolipidemic, hypoglycemic, hypotensive, antimicrobial, and anti-inflammatory properties. (3)

Rock candy or mishri is a simple carbohydrate consisting mainly of sucrose. It provides quick energy but lacks essential nutrients and should be consumed in moderation.

Does fennel seeds, rock candy and coriander seeds powder dissolve kidney stones?

The belief that fennel seeds, rock candy, and coriander seeds powder can dissolve kidney stones is rooted in traditional and folk medicine. However, there is limited scientific evidence supporting these claims.

A study by Hassan Barakat et al., published in the journal Antioxidants, found that fennel seed sprout extracts can potentially restore oxidative stability and improve kidney function. This suggests that fennel seeds and their extracts might have nephroprotective properties and could help prevent diseases related to oxidative stress. (4)

Another article published in the Avicenna Journal of Phytomedicine by Somayyeh Sadrefozalayi et al. reported that aqueous fennel seed extract had a beneficial effect on renal function in rats with polycystic ovary syndrome (PCOS). (5)

Coriander has shown diuretic effects in animal studies, specifically in a study where the aqueous extract of coriander seeds was administered to anaesthetized Wistar rats. The comparative study published in the Journal of Ethnopharmacology found that coriander extract increased diuresis, excretion of electrolytes (sodium, potassium, and chloride), and glomerular filtration rate in a dose-dependent manner. While the reference drug furosemide proved more potent, the coriander extract exhibited a similar mechanism of action. Despite these promising results in animal models, no human evidence could be found to support the diuretic effects of coriander. (7)

On the contrary, rock candy, commonly known as mishri in India, is primarily composed of sugar. A study by Yin et al. published in Frontiers in Nutrition found a significant association between higher energy intake from added sugars and an increased prevalence of kidney stones. The researchers analyzed data from 28,303 adults collected between 2007 and 2018 from the National Health and Nutrition Examination Survey (NHANES). This study offers cross-sectional evidence linking greater added sugar consumption with an increased risk of kidney stones. (8)

Although fennel seeds might protect the kidneys and coriander seeds could have diuretic effects in animals, there's no solid evidence that these, or rock candy, can dissolve kidney stones in humans. Moreover, rock candy's high sugar content increases the risk of kidney stones.

What do experts say?

Responding to the claim, Dr Vivek K Koushik, Consultant Nephrologist, Prashanth Hospitals Kolathur, Chennai, said, "While it is difficult to isolate every active compound in a spice/ food product, both fennel and coriander appear to act as a diuretic (substance which increases urine output) in animal studies which can reduce stone formation. However, no major randomised trials are available in humans to suggest that they prevent stone formation. Also, evidence suggests that consumption of added sugars like rock candy may increase the likelihood of stone formation in humans.

How are kidney stones managed?

Dr Naveen M N, Consultant, Urologist, and renal Transplant Surgeon at Gleneagles BGS Hospital, Kengeri, Bengaluru, explained that Kidney stone management can be broadly divided into two categories: "Medical treatment of kidney stones includes dietary management, disease-specific therapies, and medical expulsion therapy (MET) of stones. Fluid intake and dietary changes are important measures in preventing recurrence of kidney stones. Many trials have shown that increasing urine volume to at least 2 L/day OR 2 lit/day can reduce the recurrence of stone disease by up to 40–50%. Oxalate-rich foods like cucumber, green peppers, beetroot, spinach, soya bean, chocolate, rhubarb, popcorn, and sweet potato should be avoided. Fresh tomato juice was found to have the highest citrate and low oxalate content. Reduction of animal protein intake is suggested in both calcium oxalate and uric acid stone formers. MET is treatment with combination of drugs which facilitates the spontaneous passage of ureteric calculi. Ureteric colic is an emergency and management depends upon the severity of obstruction and degree of renal function deterioration. Approximately 90% of stones <5 mm and 15% of stones between 5 and 8 mm pass spontaneously within 4 weeks, while 95% of those larger than 8 mm require urological intervention.
For surgical management of kidney stones: Simple renal calculi are those with a stone burden of <2 cm (aggregate diameter) and normal renal anatomy. Most simple renal calculi (80-85%) can be treated successfully with shock wave lithotripsy. Complex renal calculi include stones >2 cm, such as staghorn calculi, stones occurring in kidneys with abnormal anatomy, and stones resistant to fragmentation. Percutaneous nephrolithotomy is the treatment of choice for most complex renal stones. An extensive meta-analysis found that most ureteral calculi <5 mm in diameter will pass through the urinary tract spontaneously. Spontaneous passage usually occurs within four weeks after the onset of symptoms. Flexible ureteroscopy is increasingly popular as primary treatment for proximal ureteral stones as a result of the availability of small diameter flexible ureteroscopes, ureteral access sheaths, holmium laser lithotripsy, and stone baskets0. Percutaneous nephrolithotomy is reserved for large (≥2 cm) or impacted proximal ureteral stones."

Medical Dialogues Final Take

While fennel seeds and coriander seeds have shown some health benefits, including nephroprotective and diuretic effects in animal studies, no scientific evidence or medical consensus supports the claim that these ingredients can effectively dissolve kidney stones in humans. These studies were conducted on animals, and further research needs to be done on humans to verify these effects. Moreover, rock candy, which is primarily composed of sugar, has been associated with an increased risk of kidney stones.

Hence, this claim is False.  

References

1. https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stonesReferences

2. Noreen, S., Tufail, T., Badar Ul Ain, H., & Awuchi, C. G. (2023). Pharmacological, nutraceutical, functional and therapeutic properties of fennel (foeniculum vulgare). International Journal of Food Properties, 26(1), 915–927. https://doi.org/10.1080/10942912.2023.2192436

3. Prachayasittikul V, Prachayasittikul S, Ruchirawat S, Prachayasittikul V. Coriander (Coriandrum sativum): A promising functional food toward the well-being. Food Res Int. 2018 Mar;105:305-323. doi: 10.1016/j.foodres.2017.11.019. Epub 2017 Nov 21. PMID: 29433220.

4. Barakat H, Alkabeer IA, Althwab SA, Alfheeaid HA, Alhomaid RM, Almujaydil MS, Almuziree RSA, Bushnaq T, Mohamed A. Nephroprotective Effect of Fennel (Foeniculum vulgare) Seeds and Their Sprouts on CCl4-Induced Nephrotoxicity and Oxidative Stress in Rats. Antioxidants. 2023; 12(2):325. https://doi.org/10.3390/antiox12020325

5. Sadrefozalayi S, Farokhi F. Effect of the aqueous extract of Foeniculum vulgare (fennel) on the kidney in experimental PCOS female rats. Avicenna J Phytomed. 2014 Mar;4(2):110-7. PMID: 25050308; PMCID: PMC4103710.

6. Gamage KN, Jamnadass E, Sulaiman SK, Pietropaolo A, Aboumarzouk O, Somani BK. The role of fluid intake in the prevention of kidney stone disease: A systematic review over the last two decades. Turk J Urol. 2020 Nov;46(Supp. 1):S92-S103. doi: 10.5152/tud.2020.20155. Epub 2020 Jun 5. PMID: 32525478; PMCID: PMC7731957.

7. Aissaoui, A., El-Hilaly, J., Israili, Z. H., & Lyoussi, B. (2008). Acute diuretic effect of continuous intravenous infusion of an aqueous extract of Coriandrum sativum L. in anesthetized rats. Journal of ethnopharmacology, 115(1), 89–95. https://doi.org/10.1016/j.jep.2007.09.007

8. Yin, S., Yang, Z., Zhu, P., Du, Z., Yu, X., Tang, T., & Borné, Y. (2023). Association between added sugars and kidney stones in U.S. adults: data from National Health and Nutrition Examination Survey 2007-2018. Frontiers in nutrition, 10, 1226082. https://doi.org/10.3389/fnut.2023.1226082