Kidney stones are a common urinary tract condition, forming when solid waste accumulates in the kidneys and crystallizes. According to Mayo Clinic, there are four main types of kidney stones, with calcium oxalate stones being the most common. Less common types include struvite, uric acid, and cysteine stones.

Small stones often pass naturally through urine. However, large stones can partially obstruct the urinary system, causing severe pain, vomiting, and bleeding. Kidney stones also have a high recurrence rate after 5-10 years. Adopting the following dietary habits can help limit stone formation.

Drink plenty of water

According to the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), drinking plenty of water is a simple and frequently recommended way to prevent kidney stones. Water dilutes and increases the volume of stone-forming substances in urine, making them less likely to crystallize.

Not all beverages have the same effect. Drinks such as coffee, tea, beer, wine, and orange juice pose a low risk for stone formation. Conversely, consuming large amounts of carbonated soft drinks contributes to kidney stone formation because they contain fructose, which increases the excretion of calcium, oxalate, and uric acid.

Drinking plenty of water and orange juice reduces the risk of kidney stones. *Illustration: Ngoc Pham*

Increase citrus fruit intake

According to Healthline, citric acid is an organic acid found in many fruits and vegetables, especially citrus varieties. Lemons and passion fruit are particularly rich in this plant compound.

Citric acid can help prevent calcium oxalate kidney stones by binding with calcium in urine, reducing the risk of new stone formation. This compound can also bind to existing calcium oxalate crystals, preventing them from growing and helping to eliminate them before they become larger stones.

An easy way to consume more citric acid is to eat citrus fruits, such as grapefruit, oranges, lemons, or passion fruit. You can also add a little lemon juice or orange juice to your drinking water.

Limit oxalate-rich foods

Oxalate (oxalic acid) is an antinutrient found in many foods, including leafy green vegetables, fruits, root vegetables, and cocoa. The body also produces a significant amount of this substance. High oxalate intake can increase oxalate excretion in urine. Oxalate binds with calcium and other minerals to form crystals, potentially leading to kidney stones.

However, oxalate-rich foods are often healthy, so not everyone needs to follow a strict low-oxalate diet. This diet is only recommended for individuals with hyperoxaluria, a condition characterized by high oxalate levels in urine.

Avoid high-dose vitamin C

High-dose vitamin C supplements can increase oxalate excretion in urine. However, it is important to note that vitamin C from food sources, such as lemons, is not linked to an increased risk of kidney stones.

Ensure sufficient calcium intake

A common misconception is that reducing calcium intake lowers the risk of calcium kidney stones. The reality is the opposite: dietary calcium tends to bind with oxalate in food, preventing its absorption. Consequently, the kidneys do not need to excrete oxalate through the urinary system.

Dairy products like milk, cheese, and yogurt are good sources of calcium. For most adults, the recommended daily intake is 1,000 mg of calcium. For women over 50 and individuals over 70, it is 1,200 mg.

Reduce salt intake

High sodium intake from table salt can increase calcium excretion in urine, a primary risk factor for kidney stones. The general recommendation is typically no more than 2,300 mg of sodium per day, though most people consume more. One of the best ways to reduce sodium intake is to cut back on packaged and processed foods.

Increase magnesium intake

Magnesium is an important mineral many people do not consume enough of. It is involved in hundreds of metabolic reactions, including energy production and muscle movement. Some evidence suggests magnesium can help prevent calcium oxalate kidney stones. While the exact mechanism is not fully understood, magnesium is believed to reduce oxalate absorption in the intestines.

The recommended intake for magnesium is 420 mg per day. Avocados, legumes, and tofu are good sources of this mineral. For maximum benefit, consume magnesium alongside oxalate-rich foods.

Reduce animal protein intake

Diets high in animal protein, such as meat, fish, and dairy products, are linked to a higher risk of kidney stones. This is because they can increase calcium excretion and decrease citrate levels.

Animal protein sources are rich in purines. These compounds break down into uric acid, which can increase the risk of uric acid stone formation. All food types contain varying amounts of purines. Kidneys, liver, and other organ meats have very high purine content, while plant-based foods contain less.

Anh Ngoc (Compiled)