Can Parsley Cause Kidney Stones? A Look at Oxalates and Kidney Health

November 17, 2025 •

3 min read

According to the National Kidney Foundation, about 1 in 10 people will experience a kidney stone in their lifetime. While parsley contains oxalates, a compound linked to stone formation, the question of whether parsley can cause kidney stones depends heavily on consumption levels and individual health factors. This article explores the nuanced relationship between this common herb and kidney health.

Quick Summary

Parsley contains oxalates, but normal culinary amounts pose minimal risk for most healthy people. Its diuretic properties can actually benefit kidney health. Individuals with specific conditions or those consuming large amounts, like in tea, should be more cautious.

Key Points

Oxalate Content: Parsley contains oxalates, a compound linked to calcium-oxalate kidney stones, but typical culinary servings are very small.
Normal Consumption is Low-Risk: For healthy individuals, the amount of oxalate in a normal culinary serving of parsley is too low to cause kidney stones.
Protective Properties: Parsley acts as a natural diuretic and contains antioxidants, which can help promote kidney health and prevent crystal formation.
High-Risk Individuals: People with a history of kidney stones, kidney disease, or hyperoxaluria should be cautious with their overall oxalate intake, including large doses of parsley.
Moderation is Key: Consuming concentrated forms like parsley tea or large quantities should be avoided by at-risk groups, as this significantly increases oxalate exposure.
Dietary Balance: The key to preventing oxalate-related stones is balancing overall diet and staying well-hydrated, not eliminating specific foods in moderation.

What Are Oxalates and Their Link to Kidney Stones?

Oxalates, or oxalic acid, are natural compounds found in a wide variety of plant-based foods. In the body, they can combine with calcium to form calcium oxalate crystals. When these crystals accumulate in the kidneys, they can develop into the most common type of kidney stone. While the liver produces oxalates, most are absorbed from dietary sources. However, the risk of developing a kidney stone is influenced by many factors beyond just oxalate intake, including hydration levels, diet, and genetics.

How Do Oxalates Work?

Oxalate in food comes in two forms: soluble and insoluble. Soluble oxalates are absorbed by the body, while insoluble oxalates, which are bound to minerals like calcium, are not. For most people, a diet with adequate calcium can help reduce oxalate absorption, as calcium and oxalate bind in the digestive tract and are eliminated before reaching the kidneys. For individuals prone to calcium oxalate stones, controlling dietary oxalate is a critical part of prevention.

Parsley's Oxalate Content vs. Typical Consumption

Parsley is classified as relatively high in oxalates on a weight basis. A 100g portion of raw parsley may contain between 150 and 170 mg of total oxalates. However, it is crucial to consider the typical serving size. A standard garnish or a tablespoon of chopped parsley, weighing only a few grams, contributes a very small amount of total oxalates to a meal. Furthermore, research has indicated that much of the oxalate in parsley is in the insoluble form, which is not readily absorbed by the body. Therefore, for a healthy person consuming parsley in typical culinary amounts, the risk is minimal.

Protective Qualities of Parsley for Kidneys

In addition to its oxalate content, parsley offers several properties that are beneficial for kidney health. It is a natural diuretic, meaning it can increase urination and help flush toxins and excess fluids from the body. Studies in animal models have also shown that parsley extract may decrease urinary calcium excretion, increase urinary pH, and act as a protective agent against crystal formation. The herb is also rich in antioxidants, which help reduce oxidative stress and inflammation, potentially protecting renal tissues.

High-Risk Groups and Large Consumption

While culinary consumption is generally safe, certain groups of people should exercise caution, particularly when consuming large, concentrated amounts of parsley. Individuals with hyperoxaluria, a genetic condition causing excessive oxalate excretion, are advised to limit dietary oxalates. High doses of parsley, such as those found in some concentrated teas or supplements, are more likely to significantly increase oxalate intake and potential risk. The National Kidney Foundation advises caution with various herbs and supplements for those with kidney disease.

Other High-Oxalate Foods

It's important to remember that parsley is not the only source of oxalates. Many other common foods contain significant amounts. These include:

Spinach
Rhubarb
Beets and beet greens
Nuts, including peanuts and almonds
Chocolate
Tea
Sweet potatoes

Balancing these foods with adequate calcium intake and proper hydration is key for managing risk.

Comparison of Parsley's Oxalate Content vs. Other Foods


Food (per 100g)	Total Oxalate (mg)	Typical Serving Size	Risk Level in Standard Culinary Use
Parsley, raw	150-170	1 tbsp (3.8g)	Very Low
Spinach, raw	~970	1 cup (30g)	Moderate
Rhubarb	>500	1 stalk (50g)	Moderate
Beets, raw	50-70	1/2 cup (60g)	Low
Almonds	~500	1 oz (28g)	Moderate

Conclusion

For the average healthy individual, incorporating parsley into meals in normal culinary amounts is safe and poses no significant risk of causing kidney stones. The amount of oxalate consumed in a small serving is negligible, and parsley's diuretic and antioxidant properties may even offer protective effects for kidney health. However, individuals with a history of kidney stones, specific conditions like hyperoxaluria, or those consuming large, concentrated quantities should consult a healthcare provider. Moderation and staying well-hydrated are the most effective strategies for preventing kidney stones for most people. For further reading, authoritative guidance on dietary recommendations for kidney stone formers is available from institutions like the National Kidney Foundation.

Frequently Asked Questions

For most healthy individuals, eating parsley every day in normal culinary amounts (e.g., as a garnish or seasoning) is unlikely to cause kidney stones. The oxalate content is only a concern in very large, concentrated doses or for people with pre-existing conditions.

Cooking can slightly reduce the soluble oxalate content of vegetables. However, a significant portion of parsley's oxalates are already insoluble, meaning they are not absorbed by the body. The small amount of parsley typically used makes cooking's effect on total intake negligible.

While parsley tea is traditionally used as a diuretic, studies have yielded mixed results regarding its effectiveness for kidney stones in humans. For individuals prone to stones, consuming concentrated amounts in a tea could potentially increase risk and should be discussed with a doctor.

Studies show some minor variations in oxalate content between flat-leaf and curly parsley. However, much of the oxalate in both is insoluble. The differences are not significant enough to impact risk when consumed in typical culinary quantities.

Parsley is a biennial herb with edible leaves, while parsley root is the taproot of a specific parsley variety. Research suggests that while the leaves contain oxalates, concentrated preparations like parsley root oil can contain toxins and are considered unsafe in large amounts.

If you have pre-existing kidney disease, you should avoid consuming parsley in medicinal quantities and discuss dietary changes with your healthcare provider. Parsley contains chemicals that can worsen kidney disease.

Beyond its effects on the kidneys, parsley is rich in antioxidants and vitamins A, K, and C. It supports immune function, bone health, and has anti-inflammatory properties that benefit overall health.

Large doses of vitamin C supplements have been linked to increased oxalate production in the body. However, the vitamin C from normal, food-based intake of parsley is not high enough to significantly raise this concern for most people.