Vegan Diets: Kidney Stone Risk And Prevention

A vegan diet may not cause kidney stones, but rather help prevent them. Studies have shown that a diet low in animal protein may dramatically reduce the overall probability of forming kidney stones. This is because high animal protein intake increases the likelihood of an individual having multiple stones. Conversely, a vegan diet is high in fruits and vegetables, which have a high water, potassium, and magnesium content, and a low sodium chloride content. These factors help prevent the formation of kidney stones.

High animal protein intake increases the risk of kidney stones

Kidney stones are one of the most uncomfortable afflictions, and if they block the flow from the kidneys, they can cause serious damage to the kidney itself. A study published in the 1970s found a striking relationship between the incidence of kidney stones and the consumption of animal protein. This was a population study, however, so it couldn't prove cause and effect.

This study inspired British researchers to conduct an interventional study, adding animal protein to subjects' diets and measuring stone-forming risk factors in their urine. Participants' overall probability of forming stones increased by 250% during the days they ate extra fish. The so-called "high animal protein diet" was just enough to bring intake up to that of the average American. So, Americans' intake of meat appears to markedly increase the risk of kidney stones.

By the late 1970s, we knew that the only dietary factor consistently associated with kidney stones was animal protein. The higher the intake of animal protein, the more likely the individual is to not only get their first kidney stone but to then suffer from subsequent multiple stones. This effect was not found for high protein intake in general but specifically high animal protein intake. Conversely, a diet low in animal protein may dramatically reduce the overall probability of forming stones. This may explain the apparently low incidence of stones in vegetarian societies.

In a 2014 study, researchers found that vegetarians were indeed at a lower risk of being hospitalized for kidney stones. Among meat-eaters, increased meat intake is associated with a higher risk of developing kidney stones, whereas a high intake of fresh fruit, fiber, and magnesium may reduce the risk.

The reasons given for why animal proteins are bad are because of hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia, and the acidification of the urine.

Uric acid-based stones are the second most common type of kidney stone (after calcium-based) that can be treated using a whole-food, plant-based diet. The reason a reduction in animal protein helps is not only because it reduces the production of acids within the body, but a reduction of animal protein also limits the excretion of uric acid crystals that can act as a seed to form calcium stones or create entire stones themselves. Removing meat from the diet and switching to a plant-based diet can remove 93% of uric acid crystallization risk within days.

To minimize uric acid crystallization, the goal is to get our urine pH up to ideally as high as 6.8. A number of alkalinizing chemicals have been developed for this purpose, but we can naturally alkalize our urine up to the recommended 6.8 using purely dietary means. Namely, by removing all meat, someone eating the standard Western diet can go from a pH of 5.95 to the goal target of 6.8—simply by eating plant-based.

Through dietary changes alone, we may be able to dissolve uric acid stones completely and cure patients without drugs or surgery. To summarize, the most important things we can do diet-wise are to drink 10 to 12 cups of water a day, reduce animal protein, reduce salt, and eat more vegetables and vegetarian food.

Vegetarians have a lower risk of kidney stones

In a 2014 study, hospital admissions data was used to compare in detail the prevalence of kidney stones in vegetarians and non-vegetarians. Their findings indicated that vegetarians were indeed at a lower risk of being hospitalized for kidney stones compared to those who ate meat. Among meat-eaters, increased meat intake is associated with a higher risk of developing kidney stones, whereas a high intake of fresh fruit, fiber, and magnesium may reduce the risk.

In a 1979 study, men with the highest meat consumption were more likely to be recurrent stone formers due to the increased urinary excretion of calcium, oxalate, and uric acid. This study was repeated in 1982, and vegetarians had a 40-60% decreased risk of kidney stones. Another study from 2009 found that a diet that includes high intake of fruits, vegetables, nuts, legumes, low-fat dairy products, and whole grains, some lean meats, and a low intake of sodium, sweetened beverages, and red and processed meats, cut the risk of kidney stones almost in half. This may be due to the decrease in animal protein, the higher amounts of magnesium and potassium in vegetables, or the higher amount of phytic acid in grains.

High intake of fruits and vegetables may reduce the risk of kidney stones

A vegan diet is not directly linked to the formation of kidney stones. However, some foods commonly consumed by vegans may be associated with an increased risk of kidney stones. This is because kidney stones are formed when there is a decrease in urine output or an increase in certain substances, such as minerals and salts.

Kidney stones are small, hard deposits that can cause extreme pain. They are formed when the urine becomes supersaturated with certain substances, which then crystallize and form stones. The most common type of kidney stone is calcium oxalate, which forms when calcium in the urine combines with oxalate, a chemical found naturally in many foods.

While oxalate is generally not found in animal products, many plant foods contain moderate to high levels of oxalate, and some are extremely high. For example, spinach, beets, sweet potatoes, and nuts are all high in oxalate. However, a study from the Harvard School of Public Health found that people following a plant-based diet had a lower occurrence of kidney stones.

So, how can someone on a vegan diet reduce their risk of kidney stones? Here are some tips:

• Drink plenty of water: Water helps to dilute the substances in urine that lead to stone formation. Aim for at least eight 8-ounce cups of water per day.
• Increase fruit and vegetable intake: Fruits and vegetables are necessary for any diet and can help prevent stone formation. Choose fruits with high levels of citric acid, such as oranges and lemons, as these have been shown to have a positive effect in preventing kidney stones. Vegetables rich in potassium, such as Brussels sprouts, broccoli, and kale, can also help prevent stone formation by decreasing calcium loss.
• Limit high-oxalate foods: Not all vegetables contain oxalate, but some have much higher levels than others. Limit your intake of baked potatoes with skin, bran cereals, spinach, rhubarb, Swiss chard, beets, and nuts, as these are high in oxalate.
• Combine oxalate-rich foods with calcium-rich foods: If you consume high-oxalate foods, pair them with calcium-rich foods to help your body handle oxalate. For example, have yogurt with berries or nuts, or add low-fat cheese to your spinach salad.
• Stay low on protein and sodium consumption: High protein and sodium intake can increase the risk of kidney stones. Limit your intake of animal protein, such as beef, pork, eggs, and fish, and reduce your sodium intake by limiting canned foods, packaged meats, fast food, and condiments.
• Avoid high doses of vitamin C: Too much vitamin C can increase the risk of kidney stones. Do not take more than 500 mg per day.

High animal protein intake increases the risk of multiple stones

Kidney stones are one of the more uncomfortable afflictions, and if they block the flow from the kidneys, they can cause serious damage to the kidney itself. The recurrence rate for kidney stones is 50-80%. The good news is that a whole-food, plant-based diet has been shown to help prevent, treat, and significantly reduce or eliminate the recurrence of future stones.

The only dietary factor consistently associated with kidney stones is animal protein. The higher the intake of animal protein, the more likely the individual is to have multiple stones rather than just one episode. This effect is not found for high protein intake in general, but specifically high animal protein intake. Conversely, a diet low in animal protein may dramatically reduce the overall probability of forming stones. This may explain the apparently low incidence of stones in vegetarian societies.

In a 1979 study, men with the highest meat consumption were more likely to be recurrent stone formers due to the increased urinary excretion of calcium, oxalate, and uric acid. This study was repeated in 1982, and vegetarians had a 40-60% decreased risk of kidney stones. Another study found that the average American intake of meat markedly increases the risk of kidney stones.

In a 2014 study, researchers compared the effects of salmon and cod, chicken breast meat, and burger and steak. They found that gram for gram, fish may be worse in terms of uric acid production. The overall effects were complex. Basically, stone formers should be counselled to limit the intake of all animal proteins, and not by just a little bit. Only those who markedly decrease their animal protein intake may expect to benefit.

The reasons given for why animal proteins are bad are because of hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia, and the acidification of the urine.

Uric acid-based stones are the second most common type of kidney stone (after calcium-based) that can be treated using a whole-food, plant-based diet. The reason a reduction in animal protein helps is not only because it reduces the production of acids within the body, but a reduction of animal protein also limits the excretion of uric acid crystals that can act as a seed to form calcium stones or create entire stones themselves. Removing meat from the diet and switching to a plant-based diet can remove 93% of uric acid crystallization risk within days.

Drinking water can prevent kidney stones

Drinking water is a simple yet effective way to prevent kidney stones. This is because water helps to dilute the minerals and salts in the urine that can lead to the formation of kidney stones.

The general recommendation for preventing kidney stones is to drink enough water to produce 2.5 to 3 litres of urine per day. This translates to about 13 8-ounce glasses of water. However, the exact amount of water needed may vary depending on body weight and other factors such as weather and activity level.

For example, if you live or work in hot weather or exercise frequently, you may need to drink more water to replace the fluids lost through sweating. On the other hand, if you consume a lot of salt in your diet, you may need to drink even more water, as salt can increase the concentration of minerals in your urine, making it easier for kidney stones to form.

Other Ways to Stay Hydrated

While water is the best option for preventing kidney stones, other fluids such as tea, coffee, and fruit juice can also contribute to your daily fluid intake. Citrus drinks, in particular, may offer additional protection against kidney stones due to their citrate content, which helps to prevent crystals from turning into stones.

To make staying hydrated easier, try adding flavour to your water by adding lemon or lime juice, or freezing grapes or citrus peels and using them as ice cubes. You can also try using an app to track your water intake and set reminders, or marking lines on your water bottle to indicate how much you should have drunk by certain times of the day.

Dietary Changes to Prevent Kidney Stones

In addition to increasing your water intake, making certain dietary changes can also help prevent kidney stones. Depending on the type of kidney stones you are prone to, your doctor may advise you to cut down on certain types of food.

For example, to prevent calcium stones, it is recommended to reduce the intake of salty foods such as cheese, frozen meals, canned soups, salty snacks, and bottled salad dressings. To prevent oxalate stones, it is advisable to limit foods with high oxalate levels, including spinach, rhubarb, and almonds. Finally, to prevent uric acid stones, it is best to reduce the consumption of red meat and shellfish.

By combining a sufficient water intake with a balanced diet, you can effectively reduce your risk of developing kidney stones.

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