In general terms, a ‘bezoar’ is a ball of indigestible foreign material (anything from food boluses to plant material) that collects in the stomach and fails to pass through the intestines.
Symptoms include stomach upset or distress, nausea, vomiting, diarrhea, pain.
As the most common type of bezoar, phytobezoars comprise indigestible cellulose, tannin and lignin from ingested vegetables.
Diospyrobezoars, a type of phytobezoar formed from unripe persimmons or pineapples, are particularly common in Asian countries where these fruits are common, and are especially hard to treat because of their hard consistency.
Writing in Alimentary Pharmacology & Therapeutics on December 17, S.D Ladas et al., from the department of medicine at the University of Athens, said that they had conducted this systematic meta-review of publications on gastric phytobezoars to “assess the efficacy of Coca-Cola as a dissolution therapy”.
Coke, Pepsi or common cola?
Despite the obvious Coca-Cola name check – why not Pepsi Cola or generic cola? – the study authors said their peer reviewed study was uncommissioned.
Corresponding author Dr. D Kamberoglou told BeverageDaily.com: "We decided to review papers with Coca-Cola now, because this beverage has mainly been used to dissolve phytobezoars."
Coca-Cola did not fund the review, Kamberoglou said, adding, "it is of note that the company has not found any interest and has not sent any comment about this systemic review as far as now".
The scientists wrote: “We first published a report about Coca-Cola efficacy in dissolving gastric phytobezoars in 2002.
"Since then, more than 20 reports have followed the same treatment modality."
“Our aim was to review all studies evaluating Coca-Cola dissolution therapy, concerning patients’ characteristics and outcome.”
Success as standalone treatment
After a systematic literature search, the team found that 24 papers including 46 patients had been published between 2002 and June 2012, and that in 91.3% of these cases, ‘phytobezoar resolution’ with Coca-Cola was successful in achieving either partial or complete dissolution.
“Coca-Cola alone is effective in gastric phytobezoar dissolution in half of the cases, and, combined with additional endoscopic methods, is successful in more than 90% of them.”
The beverage was successful in terms of complete dissolution as a standalone treatment (50% of cases) or combined with further endoscopic techniques (41.3%).
Phytobezoars were more likely to dissolve after initial attempts with Coca-Cola (60.6%) compared with diospyrobezoars (23%).
Coca-Cola administration is a cheap, easy-to-perform and safe procedure that can be accomplished at any endoscopy unit. Moreover, lavage can be offered at bedside or patients may drink the beverage at home.”
Variations such as Zero of Light – sweetened with aspartame – was reportedly equally effective, Ladas et al. said (quoting a Ladas et al. 2002 study).
Conservative management of phytobezoars included administering proteolytic enzymes, cellulase, carbohydrate beverages – either orally or by gastric lavage – and endoscopic fragmentation, the scientists said.
But they added that: “Endoscopic fragmentation, although efficacious as an initial treatment, is more expensive and time consuming.”
And despite the reported 100% efficacy of treating phytobezoars with cellulose, Ladas et al. said that cellulose was “not available in every country and is more expensive compared with Coca-Cola”.
"We do not think that more intervention studies need to be done," Kamberoglou told this publication.
"It seems that Coca-Cola works."
Title: ‘Systematic Review: Coca-Cola can effectively dissolve gastric phytobezoars as a first-line treatment’
Authors: S.D. Ladas, D. Kamberoglou, G. Karamanolis, J. Vlachogiannakos, I. Zouboulis-Vafiadis
Source: Alimentary Pharmacology & Therapeutics, Volume 37, Issue 2 (December 17, 2012), doi:10.1111/apt.12141
*Editorial note: Correction made in light of comment below (9/1/13)