Sorrel Safety Notes

Main Cautions

Oxalic Acid Content and Health Risks

• High oxalic acid levels in Rumex acetosa can reduce the bioavailability of minerals, particularly calcium, and may contribute to the formation of kidney stones (nephrolithiasis) in susceptible individuals (Korpelainen & Pietiläinen, 2020; Bello et al., 2019; Milani et al., 2023; Tuazon-Nartea & Savage, 2013).
• People with a history of kidney stones or renal disorders should avoid or limit consumption of sorrel and other high-oxalate greens (Milani et al., 2023; Tuazon-Nartea & Savage, 2013).
• Consuming large quantities of raw sorrel increases oxalic acid intake, which can be harmful; cooking significantly reduces oxalic acid levels and thus lowers risk (Bello et al., 2019; Tuazon-Nartea & Savage, 2013).

Drug Interactions

• Rumex acetosa extract can interfere with the absorption of certain medications, especially those transported by P-glycoprotein (P-gp) and OATP1A2, such as fexofenadine. This may reduce drug effectiveness and cause interactions with poorly water-soluble drugs (Ahn et al., 2020).

Nutritional Considerations

• While sorrel is rich in nutrients and antioxidants, the anti-nutritional effect of oxalic acid can limit mineral absorption, especially calcium (Korpelainen & Pietiläinen, 2020; Bello et al., 2019; Tuazon-Nartea & Savage, 2013).
• Sorrel is best consumed as an occasional delicacy rather than a dietary staple to minimize potential risks (Tuazon-Nartea & Savage, 2013).

Allergic Reactions and Individual Sensitivities

• Although rare, individual-specific allergies to sorrel or its phytochemicals are possible (Kota et al., 2017).

Table: Key Cautions and Recommendations

Figure 1: Summary of main health cautions and safe use recommendations for Rumex acetosa.

Deep dive: Sorrel: A Foraging Guide to Its Food, Medicine and Other Uses

Conclusion

While Rumex acetosa is nutritious and widely enjoyed, its high oxalic acid content is the primary concern, especially for those with kidney issues or when consumed raw and in large amounts. Cooking and moderation are key to safe consumption. Consult a healthcare provider if you have kidney problems or take medications that may interact with sorrel.

References

Korpelainen, H., & Pietiläinen, M. (2020). Sorrel (Rumex acetosa L.): Not Only a Weed but a Promising Vegetable and Medicinal Plant. The Botanical Review, 86, 234 – 246. https://doi.org/10.1007/s12229-020-09225-z

Bello, O., Fasinu, P., Bello, O., Ogbesejana, A., Adetunji, C., Dada, A., Ibitoye, O., Aloko, S., & Oguntoye, O. (2019). Wild vegetable Rumex acetosa Linn.: Its ethnobotany, pharmacology and phytochemistry – A review. South African Journal of Botany. https://doi.org/10.1016/j.sajb.2019.04.018

Kota, S., Dumpala, P., Anantha, R., Verma, M., & Kandepu, S. (2017). Evaluation of therapeutic potential of the silver/silver chloride nanoparticles synthesized with the aqueous leaf extract of Rumex acetosa. Scientific Reports, 7. https://doi.org/10.1038/s41598-017-11853-2

Ahn, J., Kim, J., Rehman, N., Kim, H., Ahn, M., & Chung, H. (2020). Effect of Rumex Acetosa Extract, a Herbal Drug, on the Absorption of Fexofenadine. Pharmaceutics, 12. https://doi.org/10.3390/pharmaceutics12060547

Milani, F., Bottoni, M., Giuliani, C., Colombo, L., Casiraghi, M., Colombo, P., Bruschi, P., Erba, D., & Fico, G. (2023). Alpine Diet in Valmalenco (Lombardy, Italy): Nutritional Features of Spontaneous Plants and Traditional Dishes. Nutrients, 15. https://doi.org/10.3390/nu15081988

Tuazon-Nartea, J., & Savage, G. (2013). Investigation of Oxalate Levels in Sorrel Plant Parts and Sorrel-Based Products. Food and Nutrition Sciences, 2013, 838-843. https://doi.org/10.4236/fns.2013.48109