Diet for kidney stones: What to eat or not to eat

Diet for kidney stones: What to eat or not to eat

Kidney stones, also called urinary lithiasis, are solid crystals that develop in the urinary system. When stones move in the urinary tract, they cause very severe pain often accompanied by nausea and vomiting. The purpose of the kidney stone diet is to promote optimal hydration and to limit the consumption of foods that can lead to the recurrence of stones.

The 5 essential points of the special diet kidney stones:

• Have a good hydration
• Increase your intake of vitamins and minerals
• Maintain a healthy weight
• Limit consumption of oxalates and sodium
• Moderate meat consumption

Benefits of diet in case of kidney stones

The kidney stones diet has many benefits, it allows to:

• Curb the formation of calcium oxalate
• Dissolve kidney stones naturally
• Ensure optimal nutrient intake that has a beneficial effect in cases of urolithiasis
• Find urinary comfort
• Avoid painful crises
• Recognize which foods to avoid, which contribute to the formation of oxalate

The link between kidney stones and calcium oxalate

Kidney stones usually occur after age 30 and affect men more than women. The presence of stones in the urinary tract causes various symptoms ranging from difficulty urinating to the presence of blood in the urine. The nature of kidney stones may differ but in 75 to 85% of cases, they are formed from salt or calcium oxalate.

People predisposed to overproduction of oxalate

In addition, obese individuals produce more oxalate than others. The same is true for people with high blood pressure or diabetes. Lack of physical activity can also, in the long run, lead to bone mass loss and calcium release into the bloodstream. This represents a greater risk of developing urinary lithiasis.

Diet and hydration are an integral part of the treatment of urolithiasis and their prevention. The kidney stone diet is designed to promote eating habits that prevent a recurrence.

Dietary recommendations to dissolve kidney stones naturally

The main goal of the renal stone diet is to stop the formation of calcium oxalate via diet. For this, it is recommended to adopt a healthy lifestyle and to adopt some effective measures. This sheet introduces you to the main principles of special diet kidney stones.

Recommended diet to reduce calcium oxalate formation

To reduce the formation of calcium oxalate, some foods are preferred. This is the case of calcium, potassium, vitamin B6 and citric acid. These measures must be combined with good hydration and regular physical activity to increase effectiveness.

Calcium in Diet for kidney stones

Decreased calcium intake does not result in decreased urinary excretion. On the contrary, calcium traps the oxalates present in the stomach and reduces their absorption. It is therefore recommended to consume enough calcium daily. Namely that calcium supplements are less effective than eating calcium-rich foods.

High calcium-rich foods that are effective in reducing oxalate formation are:

• Milk and dairy products
• Vegetable milks enriched with calcium
• Fish, mostly canned
• oleaginous
• legumes
• Green vegetables (parsley, dandelion, spinach, broccoli, etc.)
• Fruits (blackcurrant, orange, currant, etc.)

Hydration in Diet for kidney stones

The goal is to cause a volume of urine of more than 2 litres per day to dissolve kidney stones naturally. We must drink 2 litres of liquid, distributed throughout the day, 8 large glasses of water. It is also advisable to drink before going to bed and at least once during the night to promote the continuous elimination of urine. The urine must be very light in colour.

Water is the only essential drink, it is, however, possible to alternate with herbal teas, infused water or lemon juice. In the case of physical activity or heat, the amount of water consumed must be 3 litres. According to some studies, coffee, tea, beer, and wine reduce the formation of kidney stones. In contrast, grapefruit juice increases the formation of kidney stones.

Citric acid

Lemons in the Diet for kidney stones can be very effective.

Lemon, orange and tomato juices are rich in citric acid and make the pH of the urine more alkaline and thus reduce the formation of kidney stones via food. It is therefore interesting to use lemon and orange in cooking or to make juices and scented water.

Read more about the Diet for kidney stones…

Potassium

Low potassium intake combined with high sodium intake contributes to the formation of calcium lithiasis. We must, therefore, cover the need for potassium by choosing foods that are rich in it. Potassium sources of food for kidney stones are fruits and vegetables. You must consume at least 5 servings a day in diet for kidney stones. 

The ones that contain the most are:

• Lawyer
• Banana
• Melon
• Peach
• Artichoke
• Squash
• legumes
• Potato with skin
• Whole grains
• Green leafy vegetables

Vitamin B6 and magnesium in Diet for kidney stones

Vitamin B6 and magnesium help to solubilize calcium oxalate crystals, which reduces the risk of kidney stones. 

The source foods of vitamin B6 and magnesium are:

• Tuna, salmon, cod
• legumes
• Potato with skin
• pistachios
• Sunflower, sesame, pumpkin, flax and chia seeds
• Banana
• Green leafy vegetables
• Brown rice

Other recommended foods in the Diet for kidney stones:

• Fruits and vegetables
• Dietary fibre
• Dandelion
• antioxidants
• Omega 3
• Physical activity

Foods to avoid in cases of urinary lithiasis

Some foods are to be avoided in the kidney stone diet. Indeed, they promote the formation of oxalate and prevent the urinary system from functioning optimally. This is the case of foods rich in oxalate, sodium and animal protein.

Oxalates

Even though 90% of the oxalates are produced by our body, it is recommended to limit the consumption of rich foods such as:

• Spinach
• Rhubarb
• Celery
• Beet
• Strawberry
• Nuts
• Peanut butter
• Cocoa and chocolate
• Black tea
• Bran
• Soybean and derived products

The oxalate contained in the tea seems to have low bioavailability, that is to say, that the body absorbs only a tiny amount.

Animal protein

As part of the kidney stone diet, it is recommended to limit the consumption of animal protein to 150g per day maximum. They increase the urinary excretion of uric acid and calcium and decrease that of citrate. 

The sources of animal protein to avoid in case of kidney stones are:

• meat
• Poultry
• eggs
• Pisces
• Meats
• Cheeses (limit to 1 serving per day)

Sodium

To dissolve kidney stones naturally, it is recommended not to consume more than 2000mg of sodium per day. This would have a negative impact on blood pressure, in addition to increasing urinary calcium excretion. The main sources of sodium are industrial and prepackaged foods. In fact, more than 75% of the sodium we eat comes from processed foods such as cheeses, sausages, sauces, dehydrated dried or smoked foods.

Table summarizing the foods richest in sodium favoring the formation of kidney stones:

Vitamin C or D supplements in Diet for kidney stones

Since oxalates are a byproduct of vitamin C, it is advisable to avoid supplements that contain more than 2g per dose. However, vitamin C intake from the diet alone is safe. At the level of vitamin D supplements, it is recommended to seek the advice of a doctor.

Other foods not recommended in Diet for kidney stones:

• Saturated and trans fats
• Sweet products
• Sedentary lifestyle
• Alcohol

Kidney and Diet Calculations: Practical Tips for Reducing Sodium Intake

• Buy a maximum of “sodium-free”, “low sodium” or “no added salt” products
• Compare labels to choose products that contain the least amount of salt
• Look for foods with a sodium content below 350mg
• Buy fresh or frozen vegetables, avoid preserves
• Prefer homemade vegetable juices
• Pay attention to bread and cereal products that often contain a lot of salt, prefer their low salt versions
• Consume enough milk and yogurt and limit the cheese
• Buy natural and non-canned legumes
• Choose low-sodium mineral water
• Cook to the maximum and avoid prepared industrial products
• To add flavor to the dishes, use the condiments: pepper, garlic, onion, ginger, herbs, lemon juice, spices, etc.
• Beware of mustard and spice mixtures, often very high in salt

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