Is it okay to drink raw spinach juice? The benefits, risks, and a safer approach

December 11, 2025 •

4 min read

While spinach is a nutrient-dense powerhouse, experts warn that relying on a daily glass of raw spinach juice could backfire. The question, is it okay to drink raw spinach juice?, is crucial to consider, as high oxalate compounds in the raw leaves can interfere with mineral absorption and lead to potential health complications.

Quick Summary

Raw spinach juice is high in oxalates, which can inhibit mineral absorption and significantly increase the risk of kidney stones. Cooking spinach substantially reduces its oxalate levels, unlocking more nutrients and making it a safer option for frequent consumption.

Key Points

Oxalate Overload: Daily raw spinach juice can lead to high oxalate intake, increasing the risk of painful calcium oxalate kidney stones.
Enhanced Absorption with Cooking: Lightly cooking or blanching spinach before juicing reduces oxalates by up to 87%, increasing the absorption of beneficial minerals like iron and calcium.
Prioritise Moderation: Limiting raw spinach juice consumption to a few times per week, rather than daily, helps prevent the adverse effects of high oxalate levels.
Beware of Pesticides: Spinach is often heavily treated with pesticides, which can be concentrated during juicing. Opt for organic produce or wash thoroughly to minimize residue.
Who Should Avoid: Individuals with a history of kidney stones, thyroid disorders, or iron-deficiency anemia should avoid or consult a doctor before drinking raw spinach juice.
Add a Calcium Source: Consuming your juice with a calcium-rich food helps bind oxalates in the gut, preventing them from being absorbed into the body.

The Hidden Risks of Raw Spinach Juice

Despite its 'superfood' status, raw spinach presents several health risks, particularly when concentrated into juice. The primary culprits are oxalates, natural compounds that can bind with minerals and interfere with the body's processes.

Kidney Stone Formation: Spinach is exceptionally high in oxalates, and consuming it in concentrated liquid form delivers a powerful dose. These oxalates can bind with calcium, forming calcium oxalate crystals in the kidneys, which is a leading cause of kidney stones. Some studies have linked excessive green juice consumption to cases of acute kidney failure.
Inhibited Mineral Absorption: Oxalates are often termed 'anti-nutrients' because they bind to essential minerals like calcium, iron, and zinc, making them unavailable for your body to absorb. This is particularly concerning for individuals with conditions like iron-deficiency anemia.
Digestive Discomfort: For some, a large intake of raw spinach can lead to gastrointestinal issues, including gas, bloating, flatulence, and other irritable bowel syndrome (IBS) symptoms.
Pesticide Exposure: According to the Environmental Working Group (EWG), spinach is frequently found on its 'Dirty Dozen' list of produce with the highest pesticide residues. Juicing raw, unwashed or improperly washed spinach can concentrate these pesticides into the final product.
Thyroid Function Interference: Raw spinach contains goitrogens, natural substances that can interfere with thyroid function, especially when consumed in large quantities.

A Comparison of Raw vs. Cooked Spinach

To better understand the risks and benefits, here is a breakdown of the nutritional and health differences between consuming spinach raw and cooked.


Feature	Raw Spinach	Cooked Spinach
Oxalate Content	Very high. One cup of raw spinach contains 656mg of oxalate.	Significantly reduced by boiling (up to 87%). ½ cup of cooked spinach contains 755mg, but this reflects the smaller, denser volume of the cooked green.
Calcium & Iron Bioavailability	Low due to oxalate binding.	High. Cooking reduces oxalates, freeing up more minerals for absorption.
Vitamin C & Folate	Higher levels retained.	Some loss due to heat sensitivity.
Antioxidant Absorption	Lower availability.	Increased bioavailability of carotenoids like beta-carotene.
Fiber Content	Retained when eaten whole, but removed in juicing.	High concentration due to reduced volume.

Safely Enjoying Spinach Juice

If you still want to enjoy spinach juice, a few simple strategies can significantly reduce the risks associated with its raw form.

Blanch Your Spinach: A simple, quick step like blanching (boiling for a minute or two) can reduce the oxalate content by a significant margin. Simply dunk the spinach in boiling water, then immediately into an ice bath to stop the cooking process.
Blend with Other Ingredients: Instead of pure spinach juice, combine it with low-oxalate greens like cucumber, celery, or mint. Adding fruits such as apples or berries and a squirt of lemon juice can also enhance flavour and iron absorption.
Drink in Moderation: Limit raw spinach juice to just a few times per week, rather than making it a daily habit. This reduces your cumulative oxalate load. It is also important to drink plenty of water throughout the day to support kidney function.
Add a Calcium Source: Drinking your juice with or adding a calcium source, like a calcium-fortified plant milk, can help the calcium bind with oxalates in the gut, preventing them from being absorbed.
Choose Organic: To minimize pesticide exposure, especially with a crop known to have high residue, opt for organic spinach.

Who Should Avoid Raw Spinach Juice?

Certain individuals should be particularly cautious or avoid raw spinach juice altogether.

History of Kidney Stones: Due to the high oxalate content and direct pathway to the kidneys, those with a history of calcium oxalate kidney stones should avoid raw spinach juice.
Thyroid Disorders: People with thyroid issues, particularly hypothyroidism, should limit consumption of raw spinach to avoid interfering with thyroid function.
Iron Deficiency: While rich in iron, the oxalates in raw spinach can inhibit its absorption. Individuals with anemia may not get the benefit they seek and should opt for cooked spinach combined with vitamin C.

The Detox Myth

Many proponents of juicing claim it detoxifies the body, but this is a wellness myth. Your liver and kidneys already handle detoxification naturally and efficiently. Overloading these organs with concentrated, high-oxalate juice can make their job harder, not easier. A balanced diet rich in cooked vegetables, protein, and fibre is the most sustainable approach to long-term health.

Conclusion

While raw spinach offers certain nutritional benefits, its concentration of oxalates and potential for pesticide residue pose significant risks when consumed in juice form, especially in large quantities. For most people, a cooked spinach dish is a much safer and more effective way to absorb its beneficial minerals like iron and calcium. For those who enjoy the ritual of juicing, opting for blanched spinach or combining it with other low-oxalate ingredients and a calcium source can minimize risks. Always prioritize a balanced, varied diet over excessive consumption of any single food, even a superfood like spinach. For more detailed information on healthy dietary practices, consult authoritative health websites such as Healthline.

Safe Juice Preparation Steps

Select: Choose fresh, organic spinach if possible to minimize pesticide exposure.
Wash Thoroughly: Rinse spinach leaves under running water for at least one minute.
Blanch (Optional but Recommended): Submerge spinach in boiling water for 1-2 minutes, then transfer to an ice bath. This dramatically reduces oxalate content.
Combine Ingredients: Add blanched spinach (if used), other low-oxalate greens (cucumber, celery), and fruits (apple, lemon) to your blender or juicer.
Serve Immediately: For maximum nutritional value, drink the juice soon after preparation.

Raw Spinach vs. Cooked Spinach Nutrients


Nutrient	Raw Spinach (Approx. per 100g)	Cooked Spinach (Approx. per 100g)	Difference
Calories	23 kcal	53 kcal	Cooked has more due to volume reduction
Iron	2.7 mg	3.57 mg	Cooked has more, and it's more absorbable
Calcium	99 mg	136 mg	Cooked has more, and it's more absorbable
Vitamin K	483 mcg	493 mcg	Cooking process doesn't significantly degrade it
Folate (B9)	High	Lower due to heat sensitivity	Raw has more
Oxalates	Very High	Significantly Lower	Boiling reduces levels significantly

Frequently Asked Questions

Yes, drinking raw spinach juice, especially in large, frequent quantities, can significantly increase your risk of developing calcium oxalate kidney stones. This is due to the very high concentration of oxalates in raw spinach, which are concentrated further during juicing.

For optimal mineral absorption, cooked spinach is often better. While raw spinach has higher levels of Vitamin C and folate, cooking breaks down oxalates, making iron, calcium, and beta-carotene more bioavailable for your body.

Juicing does remove the fiber from spinach, which is important for digestion. However, it retains many vitamins, minerals, and antioxidants. The issue is not destruction, but the concentration of oxalates and the loss of fiber.

The most effective way to reduce oxalates is by boiling or blanching the spinach and discarding the cooking water. Studies show this can reduce oxalate content by up to 87%.

Yes, pairing your spinach juice with a calcium-rich food, like a fortified plant-based milk or yogurt, can help. The calcium binds to the oxalates in your digestive system, preventing them from being absorbed by your body and excreted in your urine.

Raw spinach juice is packed with antioxidants, vitamins A and C, and nitrates that can support eye health, lower blood pressure, and benefit skin. However, these benefits must be weighed against the risks of high oxalate consumption.

Even when blended into a smoothie, the oxalates in raw spinach are not neutralized. For those concerned about oxalates, using blanched spinach in your smoothie is a safer alternative.