Is it safe to drink raw spinach juice?

November 12, 2025 •

3 min read

The green juice trend has made raw spinach juice a popular morning ritual, but experts warn it may not be as harmless as it appears. A single glass can contain a highly concentrated level of oxalates, raising crucial questions about whether it is safe to drink raw spinach juice.

Quick Summary

Raw spinach juice is risky due to high oxalate concentration, which can lead to kidney stones and inhibit mineral absorption. Cooking spinach reduces oxalates and is a safer alternative.

Key Points

High Oxalate Content: Raw spinach juice concentrates oxalates, significantly raising the risk of kidney stone formation.
Mineral Absorption Inhibited: The oxalates in raw spinach bind to minerals like calcium and iron, preventing their proper absorption.
Cooking Reduces Risk: Boiling or blanching spinach can reduce its oxalate content by up to 87%, making it a much safer option.
Loss of Fiber: Juicing removes most of spinach's dietary fiber, which is important for digestion and regulating nutrient absorption.
Specific Health Concerns: Individuals with a history of kidney stones, thyroid issues, or those taking blood thinners should be especially cautious.
Safer Alternatives: Consuming cooked spinach in soups, curries, or sautéed dishes is a recommended way to get the nutrients with minimal risk.
Avoid the 'Detox' Myth: Your kidneys and liver naturally detoxify your body, and overwhelming them with high oxalate juice can be counterproductive.

The Hidden Dangers of Concentrated Oxalates

While a leafy green powerhouse, raw spinach contains high levels of oxalates, naturally occurring compounds that can pose significant health risks when concentrated. Juicing a large amount of raw spinach intensifies this issue, as one glass can contain a much higher level of oxalate compounds than a healthy body can typically handle. Moderate intake of raw spinach is generally not problematic for most, but concentrated amounts are different.

How Oxalates Impact Your Body

High oxalate intake can interfere with the absorption of essential minerals like calcium, iron, and zinc by forming insoluble crystals in the digestive tract. This can potentially lead to mineral deficiencies over time.

The Direct Link to Kidney Stones

The primary concern with high oxalate consumption from raw spinach juice is the increased risk of kidney stone formation. These calcium oxalate crystals can accumulate in the kidneys and gallbladder. Excessive intake in rare cases may lead to dietary hyperoxaluria.

Potential Side Effects and Hidden 'Anti-Nutrients'

Raw spinach also contains other compounds that can be problematic in high concentrations.

Thyroid Function Disruption: Goitrogens in raw spinach can interfere with thyroid function, especially in large quantities and for those with existing thyroid conditions.
Digestive Issues: Juicing removes fiber, allowing nutrients and oxalates to enter the system quickly, potentially causing gut problems like indigestion, bloating, gas, or triggering IBS symptoms in sensitive individuals.
Mineral Absorption Inhibitors: Phytates and lectins, in addition to oxalates, can hinder mineral absorption.

The Benefits of Spinach (When Consumed Correctly)

Spinach remains a nutrient-dense vegetable with numerous health benefits when prepared safely. Many studies focus on overall leafy green intake rather than raw juice.

Rich in Antioxidants: Cooked spinach retains high antioxidant levels.
Good for Eye Health: Lutein and zeaxanthin support vision and are present after cooking. Chopping raw spinach might increase lutein availability, but oxalate risks should be considered.
Supports Heart Health: Nitrates and potassium may help manage blood pressure.
Promotes Bone Health: Vitamin K and calcium contribute to bone strength.

Safer Preparation Methods

To enjoy spinach's benefits while minimizing risks from raw juicing, consider these methods:

Blanching: Briefly boiling spinach can reduce oxalate content significantly, potentially up to 87%.
Cooking: Sautéing, steaming, or boiling spinach makes oxalates less harmful and nutrients more available.
Mixing with Low-Oxalate Greens: Combine spinach with ingredients like cucumber, mint, or coriander in your juice to lower overall oxalate concentration.

Comparison: Raw Spinach Juice vs. Cooked Spinach


Feature	Raw Spinach Juice (High Concentration)	Cooked Spinach (Boiled or Blanched)
Oxalate Content	Very high, leading to increased risk of kidney stones.	Significantly reduced (30-87%), much safer for consumption.
Fiber Content	Minimal to none, as juicing removes most fiber.	High fiber content is retained, aiding digestion.
Mineral Absorption	Inhibited by high oxalate and phytate levels.	Enhanced due to reduced oxalate content, improving absorption.
Nutrient Bioavailability	Some heat-sensitive nutrients are preserved, but overall bioavailability is limited by anti-nutrients.	Nutrients like iron and beta-carotene become more accessible.
Kidney Stone Risk	Higher risk, especially with daily or high intake.	Very low risk for healthy individuals.
Digestive Impact	Can cause bloating, gas, and IBS symptoms in sensitive people.	Less likely to cause issues due to gentler, fiber-rich nature.

Conclusion: Prioritize Safety Over Trends

Raw spinach juice's concentrated oxalates and anti-nutrients pose risks, particularly to kidney health. Instead of raw juicing, consuming cooked spinach is a safer way to benefit from its nutrients. A balanced, whole-food diet is a more reliable approach to health. Individuals with health concerns like a history of kidney stones or thyroid conditions should generally avoid raw spinach juice. For kidney health information, resources like the National Kidney Foundation are available.

How to make spinach juice safer

If you choose to make spinach juice, consider these tips:

Blanch the spinach: Briefly boil spinach and discard the water to reduce oxalates before blending.
Dilute: Mix with low-oxalate ingredients like cucumber or low-oxalate fruits.
Add lemon juice: Vitamin C can help improve iron absorption.
Practice moderation: Drink raw spinach juice infrequently, perhaps a few times weekly, rather than daily.

By carefully preparing and consuming spinach, you can enjoy its benefits while minimizing associated risks.

Frequently Asked Questions

Yes, drinking large quantities of raw spinach juice concentrates oxalates, which can bind with calcium and lead to the formation of calcium oxalate kidney stones.

No, it is not recommended to drink raw spinach juice daily. Excessive daily consumption can increase the risks associated with concentrated oxalates, including kidney stone formation and mineral absorption issues.

To make spinach juice safer, you can blanch the spinach before juicing, mix it with low-oxalate greens like cucumber, and limit your intake to only a few times per week.

Yes, cooking methods like boiling or blanching can significantly reduce the oxalate content in spinach, with some studies indicating reductions of up to 87%.

Yes, safer alternatives include consuming cooked spinach in soups, curries, or sautéed dishes. These preparations provide the health benefits with much lower risk.

When consumed safely and in moderation (preferably cooked), spinach is rich in antioxidants, vitamins A, C, and K, and minerals like iron, which can support eye health, skin, and blood pressure.

Yes, individuals with thyroid disorders should be cautious with raw spinach juice, as it contains goitrogens that can interfere with thyroid function, especially in high concentrations.