The Medicinal History of Cascara Sagrada Bark
The most historically significant aspect of the cascara tree, specifically Frangula purshiana, is its bark. The dried, aged bark contains powerful compounds known as anthraquinone glycosides, primarily cascarosides. These active ingredients act as a stimulant laxative, triggering muscle contractions in the large intestine to promote bowel movements and inhibiting the reabsorption of water and electrolytes. For centuries, indigenous peoples of the Pacific Northwest used this "sacred bark" to treat constipation.
Following its introduction to Western medicine in the late 19th century, cascara sagrada became a widely used ingredient in commercial over-the-counter (OTC) laxatives throughout the 20th century. However, the U.S. Food and Drug Administration (FDA) issued a final rule in 2002 that banned the use of cascara in OTC laxatives due to a lack of safety and efficacy data under modern standards. Today, it is only available as a dietary supplement, which is not regulated with the same rigor as an OTC drug.
Potential Risks and Side Effects
While effective for short-term constipation relief, the long-term use or abuse of cascara sagrada is associated with serious health risks. Its stimulating effect on the colon and influence on electrolyte levels can lead to significant complications. For this reason, medical experts advise against using it for more than one or two weeks.
Potential side effects of cascara sagrada bark include:
- Abdominal cramping and pain
- Diarrhea
- Dehydration
- Electrolyte imbalance (e.g., dangerously low potassium levels)
- Heart rhythm irregularities
- Muscle weakness
- Toxic hepatitis and liver damage in severe cases
- Development of a "cathartic colon" with prolonged use
Due to these risks, cascara sagrada is not safe for use by pregnant or breastfeeding women, children, or individuals with certain gastrointestinal disorders like Crohn's disease or colitis. It is crucial to consult a healthcare professional before using any product containing cascara bark.
The Other Cascara: Coffee Cherry Tea
A separate and entirely different product also bears the name 'cascara'. This cascara is the dried husk or skin of the coffee cherry fruit, Coffea arabica, and is brewed to make a herbal tea, or tisane. The Spanish word 'cáscara' simply means 'husk', explaining the shared name but not a shared origin. This cascara is a repurposed byproduct of coffee production, offering a sweet, fruity flavor profile with notes of honey, cherry, and hibiscus. It has a much lower caffeine content than brewed coffee, comparable to green tea. The consumption of coffee cascara has become popular among coffee enthusiasts seeking a unique, low-caffeine beverage.
Environmental Impact and Harvesting Concerns
Historically, the high commercial demand for cascara sagrada bark led to significant over-harvesting from wild trees throughout the Pacific Northwest. This unsustainable practice has heavily reduced native cascara tree populations in some areas. The bark is most easily peeled in the spring and early summer, but fresh bark contains compounds that induce vomiting, so it must be aged for at least one year before use. Sustainable harvesting regulations were implemented in some regions to protect the species.
Cascara Bark vs. Coffee Cascara: A Comparison
| Feature | Cascara Bark (Sagrada) | Coffee Cascara (Husk) |
|---|---|---|
| Source Plant | Frangula purshiana (a buckthorn tree) | Coffea arabica (a coffee plant) |
| Known For | Powerful stimulant laxative properties | Herbal tea with sweet, fruity flavor |
| FDA Status | Banned in OTC laxatives since 2002; sold as supplement | No FDA issues, food product |
| Health Concerns | Risk of dehydration, electrolyte imbalance, liver issues with prolonged use | Generally safe for consumption as a tea |
| Preparation | Dried and aged bark in capsules, extracts, or tea | Dried fruit husks steeped in hot water |
The Cascara Tree's Ecological and Ornamental Value
Beyond its controversial medicinal history, the Frangula purshiana tree has significant ecological importance. It provides food and habitat for various wildlife species. Birds, including pileated woodpeckers, feast on its purple-black berries, aiding in seed dispersal. Mammals such as raccoons and bears also consume the fruit and foliage. In the fall, its leaves turn a beautiful yellow, making it a desirable ornamental tree for gardens and parks in its native Pacific Northwest range. It is noted for its adaptability to both sun and shade and its picturesque branching patterns in winter. For urban planting, however, it may require some care to thrive.
Conclusion
Ultimately, the question of what the cascara tree is known for has two distinct answers. The bark of the Frangula purshiana tree, historically known as cascara sagrada, is recognized for its powerful laxative properties, which must be used with caution due to significant safety risks. Simultaneously, the cascara from the coffee plant refers to the dried fruit husk used to brew a popular herbal tea. To navigate the different contexts, it is essential to be aware of the botanical and functional differences between the tree's bark and the coffee fruit's husk. Consumers seeking the herbal tea and those considering a supplement for constipation relief must be clear on which product they are using to ensure safety. For further reading, an authoritative resource on the safety of cascara is available from the National Institutes of Health.
A Final Note of Caution
Given the significant health risks associated with the prolonged use of cascara sagrada bark, it is imperative to consult a healthcare professional before use, especially if you have pre-existing health conditions or are taking other medications. The FDA ban on its use in OTC laxatives underscores the need for extreme care.
