Karela Can Help Prevent Kidney Stones

Chances are your first real taste of karela involved you trying to hide it on your dinner plate. The bitter taste can be quite an unpleasant surprise and it's almost certainly too much for what many would consider a rather unremarkable looking vegetable. Many simply opt to push it aside and carry on with what seems to be an easier meal.  

However, it is worth rethinking your stance, particularly for the roughly 12% of Indians who are expected to suffer from kidney stones at least once in their lifetime.  

Kidney stones are one of those unwelcome problems, which announce their arrival in a way which will be difficult to forget. The pain is excruciating, kidney stones often have a high rate of recurrence, and the traditional dietary advice of - drink more water, cut back on salt, avoid certain foods - is generally accepted to be true but not complete.

Little discussion ever seems to take place about minerals that can actively help prevent stones in the first place. Karela turns out to be a significant source of two of them.

Why Minerals Should Actually Be Taken More Seriously

The vast majority of kidney stones (around 80%) are made of calcium oxalate. Oxalate (a compound found in lots of foods) binds with calcium inside your kidneys. Once they get in too much contact with each other and an optimal environment is created they combine, form a crystal, and can grow into stones.  

Magnesium is the minerals that interrupts this whole process at the most basic level. It actually competes for oxalate with calcium – effectively getting in the way of the binding occurring in the first place. If there is enough magnesium in the urinary tract then the oxalate is happy to attach to that, and it passes harmlessly through.  

A recent (2024) randomized double-blind trial carried out with 90 individuals with calcium kidney stones showed that magnesium supplementation in them significantly reduced levels of urinary oxalate and calcium oxalate supersaturation - two key factors in kidney stone risk. The effect wasn't just a statistical one; it was a clinical one and this is far more relevant when one is trying to deal with a patient that is suffering significant pain.¹  

Phosphorus plays a complementary role. It is essential in determining how calcium is absorbed and secreted from the body. Sufficient quantities mean that less calcium is freely available to travel through the urinary tract to bind with any oxalate that may be present.

What Karela Actually contains

There are very few common vegetables, which offer as high mineral levels as karela. Their seeds in particular have high amounts of both phosphorus and magnesium – the two main players in preventing stones, which we were mentioned above. It also contains high amounts of potassium, iron, zinc and even quite a bit of Vitamin C compared to the majority of vegetables in everyday use.

The benefits of karela extend further than just the minerals it contains. It has long been known that karela has antioxidant properties.

The research on Momordica charantia (the scientific name for bitter gourd) in fact shows that it actively reduces oxidative stress within the kidneys, and a reduction in stress is known to decrease chronic kidney inflammation which is itself a precursor for stone development and kidney damage generally.

Traditional Indian, Chinese and Cuban medicine systems have all historically used the vegetable for kidney-related aliments, and the science behind it is slowly catching up.

The Blood Sugar Link

There is one other way that karela could actually help reduce kidney stone risk. Increased amounts of urinary calcium and oxalate occur when there is high blood sugar, even if it is just pre-diabetic levels. People who have diabetes or insulin resistance are more likely to suffer from kidney stones. 

Karela, however, has arguably the longest studied reputation of any food in its ability to lower blood sugar. There are known compounds called charantin and polypeptide-p within it which reduce glucose in the blood. In this sense karela is not only reducing urinary stones from minerals but also reducing one of the factors that may have initially encouraged their formation.

Getting Used To the Bitterness

While many people struggle with the bitterness, there are several simple ways to help take the edge off without sacrificing the mineral value of the vegetable.

If you soak it after slicing it in salt for about twenty minutes it removes some of the bitterness.

When cooking it, using onions, tomatoes, and a small amount of jaggery can help to offset the flavor.

Karela juice is an option, but for many it is only taken in very small quantities in the morning as the sheer willpower required to drink the juice cannot be overlooked.  

That insistent insistence by your parents to finish your karela probably had some reason to it all along. Kidney stones, once they have passed through, tend to have a way of changing your opinion on bitter foods.

FAQs

References:

1. National Library of Medicine |Effect of magnesium oxide or citrate supplements on metabolic risk factors in kidney stone formers with idiopathic hyperoxaluria

Disclaimer: This content is for general informational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider with any questions about your health or treatment options.