The recent decade of observation in public health reveals that self-care is a significant policy component, particularly for taking account of the increasing number of patients with chronic diseases. Complementary and alternative medicine (CAM) is one of the frequently adopted approaches of self-care for those who are seeking for general health improvement and for patients who are trying to manage their symptoms of chronic diseases (e.g., pain, fatigue, and depression) or the adverse effects caused by conventional medicine (e.g., nausea). Therefore, providing evidence-based information of CAM modalities is of great interest to public health for supporting effective and safe self-care. However, scientific evidence is still insufficient and focus on several modalities while CAM has a wide variety, which drives this research.
The specific concern of this review is enema that uses coffee fluid. Enema therapy has a long history of being used as a detoxification treatment. As the interest on self-care through the self-administration of CAM increased, some people are willing to use enema to maintain their health. The most well-known and widely adopted methods are colon irrigation, retention enema, and coffee enema. Water with 2 different temperatures (warm and cool) that flow alternately, diluted Chinese herbal medicine, and diluted coffee are used as enema solution for colon irrigation, retention enema, and coffee enema, respectively.
Coffee enema was initially introduced as a part of the Gerson Therapy, which was developed by Dr Max Gerson in the 1930s for the treatment of degenerative diseases such as skin tuberculosis, diabetes, and most notably, cancer. The mechanism that claimed to treat cancer is through liver and intestinal detoxification by coffee enema—the kahweol and cafestol in coffee enhance the activity of glutathione (GSH) S-transferase (GST), a major antioxidant enzyme that neutralizes free radicals by 600% to 700%. These free radicals are then absorbed by the –SH groups of GSH in the bile, becoming bile salts that are flushed out of the gallbladder into the intestines for excretion through the colon. After detoxification, cancer cells are destroyed by an allergic inflammatory reaction.
The standard procedure of coffee enema initially proposed by Gerson is as follows: add 3 rounded tablespoonful of slightly roasted drip ground coffee into approximately 1 L of boiling distilled or filtered water, and continue boiling for 3 minutes and then simmer for 15 minutes. After cooling and filtering, add water to compensate for the evaporation until it reaches about 900 mL. Prepare the solution close to body temperature, and make it flow slowly to the rectum through a tube that hangs at <45 cm above the body. In general, the process would take 12 to 15 minutes. It is recommended that coffee enema should be used twice a day.
Self-administering coffee enema is relatively simple; however, a concern has been raised because harmful consequences of using it have been reported. As the modality is adopted among laypersons for various indications as a detoxification therapy (e.g., constipation, obesity, and pain relief), a scientific investigation not only on its safety but effectiveness is necessary. Therefore, a systematic review was conducted to provide evidence-based information for the practical and safe use of coffee enema as a means of self-care. For the purpose, we intended to examine relevant outcomes indicating effectiveness or safety in all population in every types of published primary studies with or without comparators.
2.1 Literature search
Although it originated from the Gerson Therapy, coffee enema is also being used as an oriental medicine treatment. As such, 12 databases, including those of oriental and international countries, were used for comprehensive literature search. As 4 international core databases, Ovid MEDLINE, Ovid Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) were used. Utilizing Korean databases referred to a Korean guidance for conducting systematic reviews, and as a result, 5 core databases (KoreaMed, Korean Medical Database [KMbase], Korean Studies Information Service System [KISS], National Discovery for Science Leaders [NDSL], and Korea Institute of Science and Technology Information [KISTI]) and 1 database specific to oriental medicine (Oriental Medicine Advanced Searching Integrated System [OASIS]) were used. Among the core databases of China and Japan, those that allowed English search (China National Knowledge Infrastructure [CNKI], and Japan Science and Technology Information Aggregator [J–STAGE], respectively) were adopted.
The search terms were established by combining “coffee,” “enema,” and words of self-administering (“self-administer,” “self-treat,” “self-perform,” “at home”). In the international databases where Medical Subject Headings (MeSH) was available, MeSH terms of coffee and enema (exp Coffee/ AND exp Enema/) were used with keywords. In the other databases where MeSH was unavailable, only keywords were used. A manual search for additional studies was also performed by reviewing the references of relevant studies. The final update of the literature search was conducted in January 2017. The search was conducted by researchers (HS, HJS, and HS).
2.2 Study selection
All types of participants, either patients or healthy people, as well as all types of published studies, with or without comparisons, were considered. Studies were excluded if coffee enema was not self-administered. Specifically, if it was reported that the enema was performed by an oriental physician and/or at an oriental hospital, the study was excluded. Whether self-administered or not is unclear, we contacted the authors for clarification; if they did not respond, the study was excluded. For the outcomes, disease-specific biomedical indicators, patient-reported outcomes (e.g., quality of life), and adverse events were reviewed. When those outcomes were not reported and/or when it was not possible to observe the exclusive effects of coffee enema (e.g., mixed interventions), the studies were excluded. Two reviewers (HS and HS) separately performed the study selection, and any discrepancy was resolved through discussion.
2.3 Evaluation of the risk of biases
For studies that investigate the effectiveness of coffee enema, the researchers adopted the Cochrane risk of bias tool for randomized controlled trials (RCTs) and the risk of bias assessment tool for nonrandomized studies (Risk of Bias Assessment tool for Non–randomized Studies [RoBANS]). For case reports, critical appraisal checklist for case reports developed by Moola et al was used. If a case report satisfied 5 appraisal items out of 8, the case report was regarded to have an acceptable quality and thus, included in this systematic review. Two independent reviewers (HS and HS) performed the risk of bias and a consensus was reached with another reviewer (HS) in cases of inconsistency.
2.4 Data extraction
A predetermined and structured data extraction form was used. The author(s), the publication year, the study type, participant information (i.e., number, age, sex, and condition), intervention details, efficacy and safety outcomes, and the authors’ conclusions were extracted accordingly. Two reviewers (HS and HJS) separately performed the data extraction and cross-checked the data.
2.5 Data analyses
A meta-analysis was not possible because of the heterogeneity in the study designs, health conditions of the participants, specific procedures of administration, and outcome variables. Therefore, a descriptive analysis was performed.
2.6 Ethical statement
This study was carried out in strict accordance with the recommendations in the CARE and PRISMA guidelines. Institutional review board permission is not required for conducting systematic review and meta-analysis.
3.1 Literature search
From the database search, the abstracts of 11,364 studies were generated and subsequently reviewed for potential relevance. The full texts of the 297 studies with potential relevance were retrieved and screened, among which 291 were excluded by the exclusion criteria. As such, 7 case reports were selected from the database search. In addition, 2 others were identified from the manual search. Therefore, 9 case reports on self-administered coffee enema were finalized for the analysis (Fig. 1).
3.2 Evaluating the risk of biases
Most of case reports were adequately reported patient's demographic characteristics, patient's clinical history according to timeline, the current clinical condition of the patient on presentation, diagnostic tests or assessment methods, and the results. Whereas, 3 (33.3%) of 9 case reports did not clearly described the procedure of self-administered coffee enema. Because the case reports investigated the adverse cases of self-administered coffee enema, the post-intervention clinical condition was not described in all 9 case reports whereas the adverse events of unanticipated events were well-identified. Following the pre-determined criteria, all 9 case reports were found acceptable quality and therefore; included in this systematic review. The results are summarized in Table 1.
3.3 Safety of self-administered coffee enema
Among the 9 case reports, 3 were from the United States,[12–14] 5 were from Korea,[15–19] and 1 was from Japan. The characteristics and results are summarized in Table 2.
Seven relatively recent ones[14–20] reported similar adverse events induced by self-administered coffee enema. Although the ages of the patients in these case reports varied, they were mostly women and had used coffee enema to relieve constipation or bowel cleansing. The intervention of coffee enema was described in 4 case reports,[15–18] which were mostly comparable to the standard method of Gerson, except Lee et al reported higher temperature and longer retaining time. After self-administering coffee enema, the patients of the 7 case reports experienced pain in lower abdomen or occasionally, in the anal region with bloody stool. As a consequence of self-administering coffee enema, colitis was diagnosed in 4 case reports[16–18] and in the other 3,[14,19,20] rectal burn or perforation was observed through medical imaging.
The mechanism by which coffee enema induced the burn suggested in 5 case reports among the 7 relatively recent case reports. Two[14,19] suggested that the high temperature of the coffee fluid might be the cause, and it was proposed that the coffee should be cooled off before use. Other 3[16–18] more explored potential mechanisms for the coffee enema-induced adverse events based on those mechanisms associated with the adverse effects of enema therapy in general. These include the high temperature and/or high pressure of the enema fluid, the chemical residues (e.g., cleanser or disinfectant) inside the catheter, or the thermal injury caused by the catheter. While none of those were found as plausible causes of colitis, the coffee fluid itself was newly proposed to be the most plausible cause.
As cited in the 3 case reports, caffeine was shown to induce inflammation in animal experiments—it induced smooth muscle relaxation through the adenosine A2b receptor, suppressed the functions of mononuclear cells and macrophagocytes, and increased the emission of mast cell mediators. Furthermore, 1 of the 3 case reports was concerned that the coffee fluid contained a mixture of compounds of natural occurrence—including chlorogenic acid, caffeine, cafestol, and kahweol—none of which should be ruled out for a cause of colitis.
Two case reports in the 1980s[12,13] reported more critical adverse events that are complicated by patient conditions compared with the recent 7 case reported elaborated above. The status of the 3 patients in the 2 early case reports was fragile because of fatal diseases: 2 had advanced breast cancer with metastases and 1 had multiple diseases—colitis or cholecystitis, achlorhydria, degenerative arthritis, and cholelithiasis—with severe right upper-quadrant pain.
The case report of Eisele and Reay included one patient with cancer and another with multiple diseases, who rejected the conventional treatment at hospitals and administered coffee enema by themselves at a high frequency to relieve the symptoms caused by their diseases; both patients died shortly thereafter. The autopsy results revealed “low-salt patterns” (i.e., low sodium and chloride levels, and a relatively low potassium level) in both deaths. The authors concluded that it is induced by coffee fluid because it did not contain sodium and chloride, and that the excessive use of this fluid produced osmotic concentration gradients by which sodium and chloride levels drastically decreased to depletion levels. Such electrolyte imbalance was found as the most plausible cause of the deaths.
In Margolin and Green, a breast cancer patient who had metastasis to the liver began frequent self-administration of coffee enema. Later, this patient experienced hepatic failure and died thereafter. Although bacteremia that results from enema use is rare because of the clearance of the hepatic reticuloendothelial system, the stool and blood cultures obtained before death revealed polymicrobial enteric septicemia in this patient. For this reason, the author believed that the septicemia was induced by coffee enema under the condition of a severely compromised hepatic function and portal hypertension.
All 8 case reports with conclusions[12–19] warned against the self-administration of coffee enema because of the absence of scientific evidence on the effectiveness and proper indication for administration, and, mostly, because of possible adverse events of which the mechanism is not yet clarified.
3.4 Effectiveness of self-administered coffee enema
No studies reported the effectiveness of self-administered coffee enema.
This systematic review examined the effectiveness and safety of coffee enema as a means of self-care. Unfortunately, this systematic review did not find any reports on the clinical effectiveness of self-administered coffee enema in the literature. Only there were 2 case reports that report the effectiveness of coffee enema as sole intervention, which were administered by an oriental physician. According to the reports, coffee enema was effective for relieving constipation as caffeine increased the intestinal motility when absorbed in the intestinal mucosa, and decreasing lipids and cholesterol as well as improving thyroid function.
In regards to safety, based on acceptable quality of evidence, this systematic review revealed the risk of adverse events caused by the self-administration of coffee enema, which mostly include rectal burns and colitis. So far, the case reports in this systematic review could not clarify the mechanism of the adverse events and thus; asked for caution to use coffee enema by oneself.
On the matter of how much and why risky, we searched for more evidence on adverse events of coffee enema, and found 2 case reports. One reported 1 case of colon and rectum injury after coffee enema by an oriental physician. On the other hand, another case report reported 2 minor adverse events (i.e., nausea and abdominal inflation, respectively) among 42 cases while using coffee enema to treat constipation. With evidences of serious adverse events of coffee enema by themselves, and inconsistent evidences by oriental physicians, the possibility is that a conductor's level of skill is related to the safety issue. However, with very limited quantity and quality of the related evidences, we believe trials investigating self-administered coffee enema are needed to draw more concrete conclusions on either in terms of effectiveness or safety with plausible mechanism.
Meanwhile, we would like to address more about caffeine which was suggested as a possible contributing substance in both side of case reports that reported adversity and effectiveness. There were 2 pharmacological trials[24,25] that specifically investigate whether coffee enema is effective or harmful because of its caffeine content. The results found that neither nor adversity was caused by caffeine. Therefore, the available evidence so far does not support caffeine as a substance that produces benefits or adverse events in the administration of coffee enema.
We declare several limitations of this systematic review. First, it is possible that the evidence is incompletely reviewed, which is a common concern when conducting a systematic review. Second, the quantity and quality of the included studies might be insufficient to draw a solid conclusion. Thus, further studies on the safety and effectiveness of the self-administration of coffee enema are needed in the future.
This systematic review was conducted to provide evidence utilized for public health information on the safe and effective use of coffee enema as a means of self-care. Despite several limitations, this systematic review clearly evidences potential adverse effects of self-administered coffee enema while its effectiveness is unclear. Therefore, coffee enema as a CAM modality cannot be adopted for self-care.
Conceptualization: Hyun-Ju Seo.
Investigation: Heejung Son, Hyun Jin Song, Heeyoung Lee, Sun Mi Choi, Sanghun Lee.
Visualizing: Hyun Jin Song.
Supervision: Hyun-Ju Seo.
Writing – original draft: Heejung Son and Hyun Jin Song.
Writing – review & editing: Hyun-Ju Seo, Heeyoung Lee, Sun Mi Choi, Sanghun Lee.
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