Are Spanish Peanuts High in Oxalates? What You Need to Know

December 1, 2025 •

4 min read

According to a study on the soluble and insoluble oxalate content of nuts, Spanish peanuts contain a moderate level of soluble oxalate, averaging around 173 mg per 100g. Understanding these levels is crucial for anyone monitoring their oxalate intake, especially when considering the health implications related to kidney stones.

Quick Summary

Spanish peanuts have a moderate-to-high oxalate content, with significant levels of the more absorbable soluble form. Their suitability for a low-oxalate diet depends on portion control and individual health needs.

Key Points

Oxalate Level: Spanish peanuts are moderate to high in oxalates, specifically having significant levels of the more absorbable soluble form.
Comparison: Their oxalate content is higher than low-oxalate options like pistachios but lower than very high-oxalate nuts like almonds.
Dietary Strategy: Pair Spanish peanuts with calcium-rich foods like yogurt or milk to help bind oxalates in the gut and reduce absorption.
Portion Control: Individuals on a low-oxalate diet should practice strict portion control when consuming Spanish peanuts.
Alternatives: Safe, low-oxalate alternatives for snacking or recipes include pistachios, chestnuts, sunflower seeds, and pumpkin seeds.
Processing Matters: The preparation method, such as roasting, can affect the final oxalate content of peanuts.
Individual Needs: Dietary modifications for oxalate intake should be personalized and preferably discussed with a healthcare professional.

What are Oxalates and Why Monitor Them?

Oxalates, or oxalic acid, are naturally occurring compounds found in many plants. When consumed, they can bind with minerals like calcium in the body. While this process is normal for most people, for individuals with a history of calcium oxalate kidney stones, or those with certain intestinal issues, excessive oxalate absorption can lead to problems. The concentration of oxalates varies significantly between different foods and even between varieties of the same food. For example, some nuts are notoriously high in oxalates, while others are relatively low.

There are two types of oxalates in food: soluble and insoluble. Soluble oxalates are the ones most readily absorbed by the body in the digestive tract, and therefore, they are of greater concern for those managing their oxalate intake. Insoluble oxalates are less likely to be absorbed and are generally excreted from the body.

The Oxalate Profile of Spanish Peanuts

When examining the question "Are Spanish peanuts high in oxalates?", it's important to look at both the overall amount and the type of oxalate present. Research has shown that Spanish peanuts are in a middle-of-the-road category when compared to a wide range of other nuts. A key study published in the journal Food Chemistry found that Spanish peanuts contained approximately 173.2 mg of intestinal soluble oxalate per 100g. Intestinal soluble oxalate is the type that is most likely to be absorbed, making this a significant figure for those on a restrictive low-oxalate diet, which typically aims for less than 100 mg per day.

This places Spanish peanuts in a group with other moderately high oxalate nuts like cashews and pecans, but distinctly lower than nuts like almonds or Brazil nuts, which are very high in oxalates. The processing of peanuts can also affect the final oxalate content. Roasted peanuts, for instance, may have different oxalate levels than raw peanuts.

Spanish Peanuts vs. Other Varieties

While all peanuts contain oxalates, the specific content can vary slightly between market types due to differences in composition. Spanish peanuts are a smaller-seeded variety known for their reddish-brown skin and nutty flavor. They also have a higher oil content compared to other types like Runners. A study analyzing the nutritional and bioactive composition of Spanish, Valencia, and Runner peanuts did not focus specifically on oxalates, but did highlight differences in their protein and fatty acid profiles. The core takeaway is that while there might be minor variations, all standard peanuts (including Spanish, Runner, and Valencia) should be considered a moderate-to-high oxalate food source, with Spanish peanuts explicitly analyzed and found to have a significant soluble oxalate fraction.

Oxalate Content Comparison: Spanish Peanuts vs. Other Nuts

For those managing their intake, a direct comparison is helpful. The following table highlights the intestinal soluble oxalate content (the most absorbable kind) for 100g of various nuts based on scientific research.


Nut Type	Intestinal Soluble Oxalate (mg/100g)	Oxalate Category	Notes
Almonds	222.7	High	Among the highest oxalate nuts.
Brazil Nuts	304.5	Very High	Significantly higher than most nuts.
Cashews	216.8	High	Higher than Spanish peanuts.
Spanish Peanuts	173.2	Moderate-to-High	Moderate amount of soluble oxalate.
Pecans	155.1	Moderate-to-High	Similar to Spanish peanuts.
Pistachios (roasted)	76.5	Low	A much lower oxalate option.
Chestnuts	72.3	Low	Very low oxalate content.

Incorporating Spanish Peanuts into a Low-Oxalate Diet

For people who enjoy Spanish peanuts but need to limit oxalates, moderation and specific dietary strategies are key. The National Kidney Foundation provides guidance on managing oxalate intake to prevent kidney stones.

Pair with Calcium: Eat Spanish peanuts alongside a calcium-rich food. The calcium can bind to the oxalates in the gut, preventing them from being absorbed into the bloodstream. A glass of milk, a serving of yogurt, or a sprinkle of cheese can help.
Portion Control: Keep serving sizes small. Instead of a large handful, stick to a small, controlled portion to keep oxalate intake in check.
Stay Hydrated: Drinking plenty of water helps to dilute urine and flush oxalates from the body, which can help prevent crystal formation.
Diversify Your Snacks: Don't rely solely on peanuts for your nut intake. Alternate with lower-oxalate alternatives to reduce overall consumption.

Lower Oxalate Alternatives to Spanish Peanuts

If Spanish peanuts pose too great a risk for your health needs, several tasty alternatives are lower in oxalates.

Pistachios: Roasted pistachios are a great low-oxalate option with about 76.5 mg per 100g.
Chestnuts: These offer a very low oxalate content, making them a safe choice.
Macadamia Nuts: Raw macadamia nuts contain a low amount of oxalates.
Sunflower Seeds: These seeds are very low in oxalates and can be used in place of peanuts in many recipes.
Pumpkin Seeds: Another low-oxalate seed choice with many nutritional benefits.

Conclusion

In summary, Spanish peanuts are considered a moderate-to-high oxalate food, primarily due to their soluble oxalate content. While not as high as almonds or Brazil nuts, they contain enough to warrant careful consideration for individuals following a low-oxalate diet, such as those with a history of calcium oxalate kidney stones. By practicing portion control, pairing them with calcium-rich foods, and exploring lower-oxalate alternatives like pistachios or sunflower seeds, it is possible to manage your dietary oxalate intake effectively while still enjoying a nutritious diet. It is always recommended to consult with a healthcare professional or registered dietitian for personalized advice regarding your specific dietary needs.

For more detailed guidance on managing kidney health, please refer to the National Kidney Foundation guidance.

Frequently Asked Questions

Scientific studies show that both Spanish and other varieties of peanuts are in the moderate-to-high oxalate category. A specific study measured Spanish peanuts at 173.2 mg of intestinal soluble oxalate per 100g, while standard roasted peanuts were at 115.8 mg per 100g, but other studies show variations.

For those on a restrictive low-oxalate diet (less than 100 mg/day), a standard serving of Spanish peanuts (around 1 ounce or 28g) may still contribute a notable amount of your daily total. Portion control is essential and should be discussed with a dietitian.

The effect of processing on oxalate content can be complex and depends on the specific method. Some sources suggest that roasted peanuts may have higher oxalates compared to raw ones, while the soluble oxalate content can also be influenced by cooking. The best approach is to consider both raw and roasted varieties as moderate-to-high sources.

Peanut butter is also a moderate-to-high oxalate food, as it is made from peanuts. The oxalate content can vary depending on the type and brand, so moderation is key. Small amounts can be tolerated by some individuals, especially if paired with a calcium source.

Lower oxalate nuts include pistachios, chestnuts, and macadamia nuts. Additionally, seeds like sunflower seeds and pumpkin seeds are good, low-oxalate alternatives.

While Spanish peanuts are a source of oxalates, which contribute to calcium oxalate kidney stones in susceptible individuals, consuming them alone does not directly cause kidney stones in most healthy people. Excessive consumption combined with other high-oxalate foods is the primary concern for at-risk individuals.

Yes, Spanish peanuts are rich in nutrients like protein, fiber, healthy fats, and vitamins. For those not sensitive to oxalates, they are a nutritious snack. The oxalate risk is primarily for individuals with a history of or susceptibility to kidney stones.