Cascara Sagrata
Also known as: Cascara sagrada, Bitter bark, Buckthorn, Cascararinde, Chittem bark, Cortex rhamni purshianae, Purshiana bark, Sacred bark, Rhamnus purshiana DC
Overview
Cascara sagrada is a herbal supplement derived from the bark of the Rhamnus purshiana tree, native to North America. It has been historically used as a natural stimulant laxative, primarily for the treatment of constipation and bowel cleansing. Its laxative properties are attributed to its content of anthraquinones, such as cascarosides and emodin. While traditional use is extensive, the scientific evidence supporting its efficacy and safety is considered moderate and somewhat dated. The FDA, in 2002, declared nonprescription cascara laxative products as no longer safe and effective due to insufficient supporting evidence and safety concerns, particularly regarding long-term use. It is generally recommended only for short-term relief of acute constipation.
Benefits
The primary benefit of Cascara sagrada is its laxative action, which helps to increase bowel movement frequency and improve stool consistency. This effect is observed in short-term use for constipation relief. Systematic reviews and randomized controlled trials (RCTs) indicate that cascara can alleviate constipation symptoms, though it has not been shown to be superior to other laxatives or fiber supplementation. For instance, a systematic review by Mueller-Lissner et al. (2010) found no clinically important benefit over placebo or other laxatives, noting safety concerns. Another systematic review and meta-analysis in Frontiers in Psychiatry (2021) suggested some efficacy for herbal medicines, including cascara, in relieving constipation, particularly in specific populations like those with antipsychotic-related constipation, though heterogeneity in study designs was high. Broader therapeutic benefits, such as metabolic or anti-inflammatory effects, are largely unsupported by high-quality human trials. Benefits are typically observed within hours to days of administration, but due to safety concerns, its use is strictly recommended for short-term periods only.
How it works
Cascara sagrada exerts its laxative effects through its active compounds, primarily anthraquinones like cascarosides and emodin. Upon ingestion, these compounds are metabolized by gut bacteria in the colon into active metabolites. These metabolites then stimulate the enteric nervous system and directly affect epithelial cells in the colon. This dual action leads to increased colonic motility (peristalsis) and enhanced fluid and electrolyte secretion into the intestinal lumen. The increased peristalsis propels stool through the colon, while the increased fluid content softens the stool, collectively promoting laxation. The oral bioavailability of the parent anthraquinones is limited, with their activity largely dependent on this microbial conversion.
Side effects
While short-term use of Cascara sagrada is generally tolerated, its overall safety for long-term use is questionable. Common side effects, occurring in more than 5% of users, include abdominal cramps and diarrhea. With prolonged use, uncommon side effects (1-5%) such as electrolyte imbalance, particularly potassium depletion, can occur. A rare side effect (less than 1%) is melanosis coli, a benign pigmentation of the colon, which typically reverses after discontinuation. Cascara sagrada is contraindicated in several populations: children under 10 years of age, pregnant women due to potential emmenagogue and abortifacient effects, and breastfeeding mothers as active compounds can pass into breast milk. It should also be avoided by individuals with inflammatory bowel diseases (IBS, Crohn’s disease, ulcerative colitis), appendicitis, or undiagnosed abdominal pain. Although no well-documented drug interactions are widely reported, caution is advised, especially with medications that can be affected by electrolyte disturbances (e.g., diuretics, corticosteroids, cardiac glycosides).
Dosage
The typical dosage for Cascara sagrada varies depending on the preparation. For dried bark, a common dose is 1 gram. Fluid extracts are often used in doses of 2–6 mL, while dried bark extracts typically range from 100–300 mg. The minimum effective dose is not clearly established, and dosing can vary significantly between different products and individual needs. It is crucial to note that the maximum safe dose is not well-defined, and prolonged or excessive use significantly increases the risk of adverse effects, including electrolyte imbalances and dependency. Cascara sagrada is strictly recommended for short-term use only, typically for a few days up to a few weeks, to alleviate acute constipation. Its absorption and efficacy are influenced by the gut microbiota. While no specific cofactors are required for its action, incorporating fiber supplementation into the diet may help reduce reliance on stimulant laxatives like cascara.
FAQs
Is cascara sagrada safe for long-term use?
No, long-term use of cascara sagrada is strongly discouraged due to the risk of electrolyte imbalance, potential dependency, and a benign colon pigmentation called melanosis coli.
How quickly does cascara sagrada work?
Cascara sagrada typically begins to exert its laxative effects within 6 to 12 hours after oral administration, as its active compounds require metabolism by gut bacteria.
Can cascara sagrada be used during pregnancy?
No, cascara sagrada is contraindicated during pregnancy due to its potential emmenagogue and abortifacient effects, which could pose risks to the pregnancy.
Is cascara sagrada effective for chronic constipation?
Evidence does not support the long-term efficacy or safety of cascara sagrada for chronic constipation. Fiber supplementation and lifestyle changes are generally preferred for chronic management.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/24795773/ – This systematic review by Mueller-Lissner et al. (2010) evaluated the efficacy and safety of various laxatives, including cascara, for chronic idiopathic constipation. It concluded that cascara did not demonstrate a clinically important benefit over placebo or other laxatives and highlighted existing safety concerns, contributing to the FDA's decision to reclassify it.
- https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2021.610171/full – This systematic review and meta-analysis from Frontiers in Psychiatry (2021) investigated herbal medicines, including cascara, for antipsychotic-related constipation. It found some efficacy for herbal formulations in relieving constipation, though the high heterogeneity among studies and the use of mixed herbal preparations were noted as limitations.
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8937286/pdf/atlantamsj140959-0015.pdf – This narrative review, 'Therapeutical Notes on Cascara Sagrada' (PMC 2022), provides clinical insights into cascara's mechanism as a laxative. It reinforces the understanding of its action and discusses safety concerns associated with prolonged use, as well as contraindications, aligning with general clinical guidelines despite being a lower evidence-level descriptive review.
