Kidney stones are a common and painful problem. Wouldn’t it be nice if you could just wash away those pesky crystals with a few glasses of lemonade? Though it’s not quite that simple, a new study shows that certain substances in lemon juice can break down kidney stones and prevent them from forming again.
New research could now present a more pleasant solution for kidney stone sufferers. According to the study, certain nanoparticles in lemons (amongst other things) known as extracellular vesicles, can prevent stone formation and thus prevent kidney stones.
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Kidney stones form when minerals crystallise and clump together inside the kidneys. Often, these sharp-edged lumps then make it into the urinary tract. Although the stones sometimes leave the body of their own accord, the process is often accompanied by severe pain as the sharp stones cut into tissue on their way out. If the kidney stones are too large or don’t pass out of the body on their own, the patient has no choice but to get surgery to remove the painful deposits.
Kidney stones (more accurately, calcium oxalate stones) can form when there’s too much oxalate in the body. Oxalate is found in numerous foods, including spinach, rhubarb, chocolate and nuts. However, the body also produces the substance on its own, for example, when breaking down vitamin C. Oxalate can then form a bond with calcium, crystallise as calcium oxalate and accumulate in the kidneys. But this doesn’t necessarily cause kidney stones. Instead, a combination of factors is responsible, with genetic predisposition, dietary habits, fluid intake and other individual risk factors all fostering the development of the condition.
Lemon juice is a well-known home remedy for kidney stones. It’s already known in scientific circles that citric acid can foster the absorption of minerals that could otherwise develop into kidney stones. But here’s the rub. Who actually enjoys drinking a glass of pure lemon juice every day? Hardly anyone, as a clinical trial demonstrated. During the study, patients with recurrent kidney stones were supposed to drink 120 millilitres of lemon juice daily to prevent the stones from forming again. Even the best of remedies can’t do anything unless it’s taken. In addition, citric acid has the undesirable side effect of attacking tooth enamel when drunk frequently.
So the researchers set out to find the exact active ingredient in citric acid that inhibits kidney stone formation, hoping to make it more palatable to patients. Consequently, they came across vesicle-like nanoparticles, that is, tiny sacs filled with molecules such as fat, protein and DNA. These nanoparticles are also found elsewhere, such as in ginseng, grapefruit and dandelion. The study results suggest that these particles slow the development of calcium oxalate crystals, the most common cause of kidney stones. The researchers were able to demonstrate this in rats. The particles can also soften existing stones and make them less sticky, making them easier to remove.
So is it as easy as drinking a couple of glasses of lemonade to literally flush out the problem? Not quite. So far, scientists have only been able to demonstrate the effect of extracellular vesicles in lemon juice on rats. Further studies are needed to confirm the results for humans. There’s also another unanswered question, namely how many of the effective substances would actually be present in lemonade. When it comes to «real» lemon juice, or nanoparticles isolated from lemons, however, there’s certainly reason to hope. The saying «if life gives you lemons, make lemonade» springs to mind.
If you’re going to drink to rid yourself of kidney stones, drink water. When the kidneys have enough fluid available, the substances that can lead to kidney stone formation are more easily excreted. This means you can effectively prevent stone formation by keeping your kidneys active through adequate hydration. What’s more, drinking enough water is beneficial in its own way too. I can only recommend this after my own «I did it!» experience of drinking 2.5 litres of water a day:
