Robin Harford Sambucus nigra (black elderberry) is widely used in foods and supplements for its antioxidant and health-promoting properties, but consuming raw or improperly processed parts can pose health risks due to naturally occurring toxic compounds.
Key Safety Concerns
- Cyanogenic Glycosides: Elderberries, especially unripe berries, leaves, and stems, contain cyanogenic glycosides, which can release toxic cyanide when metabolised. While ripe berries have lower levels than other plant parts, improper processing or consuming large amounts of raw berries can cause nausea, vomiting, diarrhea, and, in severe cases, cyanide poisoning (Avena et al., 2024; Senica et al., 2017).
- Lectins: Raw elderberries also contain lectins, which can cause gastrointestinal distress. Heat treatment (cooking, boiling) effectively destroys these lectins and cyanogenic glycosides, making the berries safe to eat (Avena et al., 2024).
- Processing Methods: Proper processing, such as cooking, fermentation, or ultrasonic treatment, is essential to reduce toxic compounds and ensure food safety. Fermentation and heat are particularly effective at lowering cyanogenic glycoside content (Avena et al., 2024; Senica et al., 2017).
- Variation by Location and Ripeness: The concentration of toxic compounds varies with plant part, ripeness, and growing conditions. Berries from higher altitudes may contain more cyanogenic glycosides (Senica et al., 2017).
Table: Toxic Compounds and Mitigation in Sambucus nigra
| Compound | Risk if Consumed Raw | Mitigation Method | Citations |
|---|---|---|---|
| Cyanogenic glycosides | Cyanide poisoning | Cooking, fermentation | (Avena et al., 2024; Senica et al., 2017) |
| Lectins | GI distress | Cooking | (Avena et al., 2024) |
| Unripe berries/leaves | Higher toxicity | Avoid consumption | (Avena et al., 2024; Senica et al., 2017) |
Figure 1: Summary of toxic compounds in Sambucus nigra and safe preparation methods.
Additional Considerations
- Adulteration and Mislabeling: Commercial elderberry products may be adulterated or mislabeled, so sourcing from reputable suppliers is important (Gafner & Brinckmann, 2023).
- Clinical Evidence: While elderberry is generally recognized as safe when properly prepared, clinical trials on long-term safety are limited (Ulbricht et al., 2014; Liu et al., 2022).
Dig deeper. Elder: A Foraging Guide to Its Food, Medicine and Other Uses
Conclusion
Sambucus nigra is safe to eat when properly cooked or processed, but raw or unripe berries, leaves, and stems should be avoided due to the risk of cyanide poisoning and gastrointestinal upset. Always ensure elderberry products are from reputable sources and prepared using methods that neutralise toxic compounds.
References
Avena, A., Ozola, L., & Ķeķe, A. (2024). Sambucus nigra fruits and their processing solutions: a review. Research for Rural Development. https://doi.org/10.22616/rrd.30.2024.011
Ulbricht, C., Basch, E., Cheung, L., Goldberg, H., Hammerness, P., Isaac, R., Khalsa, K., Romm, A., Rychlik, I., Varghese, M., Weissner, W., Windsor, R., & Wortley, J. (2014). An Evidence-Based Systematic Review of Elderberry and Elderflower (Sambucus nigra) by the Natural Standard Research Collaboration. Journal Of Dietary Supplements, 11, 120 – 80. https://doi.org/10.3109/19390211.2013.859852
Liu, D., He, X., Li, H., Feng, Y., Zou, L., & Gan, R. (2022). Elderberry (Sambucus nigra L.): Bioactive Compounds, Health Functions, and Applications.. Journal of agricultural and food chemistry. https://doi.org/10.1021/acs.jafc.2c00010
Gafner, S., & Brinckmann, J. (2023). Adulteration of European Elder (Sambucus nigra) Berries and Berry Extracts. **. https://doi.org/10.59520/bapp.bapb/dgms7687
Senica, M., Stampar, F., Veberič, R., & Mikulič-Petkovšek, M. (2017). The higher the better? Differences in phenolics and cyanogenic glycosides in Sambucus nigra leaves, flowers and berries from different altitudes.. Journal of the science of food and agriculture, 97 8, 2623-2632. https://doi.org/10.1002/jsfa.8085