The article, titled "The Adulteration of Commercial 'Grapefruit Seed Extract' with Synthetic Antimicrobial and Disinfectant Compounds," will be published in peer-review journal HerbalGram and reviews 10 published analytical studies on the extracts since 1991.
Grapefruit seed extract (GFSE) has been on the natural products market for at least 30 years as an ingredient in or preservative for cosmetics and related preparations for external use, and also in dietary supplements.
Possible adulteration
The ingredient is supposedly an extract of the seeds of the common grapefruit and has been touted in modern, popular literature as a natural antimicrobial agent for both topical and internal use.
As noted in the HerbalGram article, which is solely a review on previous analysis, contemporary research shows that "a significant amount, and possibly a majority, of ingredients, dietary supplements and/or cosmetics labeled as or containing grapefruit seed extract are adulterated, and any observed antimicrobial activity is due to synthetic additives, not the grapefruit seed extract itself."
According to ABC, these analytical studies performed on proprietary GFSE products have shown the presence of non-naturally occurring chemicals, including the microbicides benzalkonium chloride, benzethonium chloride, triclosan, and methyl p-hydroxybenzoate.
Uncertainties
"This situation is especially curious and troubling," said ABC founder and executive director Mark Blumenthal, "given the fact that there does not appear to be any historical or traditional medicinal use of grapefruit seed, or preparations made from it in any treatises or monographs in traditional literature, pharmacopeial compendia, etc.
"We do not know whether all products claiming to contain 'grapefruit seed extract' are adulterated," said Blumenthal. "But, as our article shows, there is ample evidence in the scientific literature to raise serious concerns about the probable adulteration of such products."
According to the article’s author John Cardellina, PhD, over time, the synthetic microbicides present in the GFSE products analyzed have changed, making a stronger case for the probability of adulteration.
"The fact that the antimicrobial components found in GFSE changed from 1991 to 2008 not only argues against such in situ synthesis (i.e., occurring naturally or synthesized in the processing of grapefruit seed material itself), but is suggestive of efforts by manufacturers of these commercial materials to stay one step ahead of analytical methods to detect adulteration," he states.
Call to the FDA
The United States Food and Drug Administration (FDA) has previously issued Warning Letters to several companies for illegal drug claims describing antimicrobial and antifungal effects of GFSE-containing products sold as dietary supplements and cosmetics, among other violations for those products cited by the agency.
"We believe that the FDA should immediately investigate the apparent adulteration of GFSE-containing products and take appropriate regulatory action where necessary," Blumenthal added.
"This includes testing commercial GFSE-containing products, inspecting manufacturing facilities, reviewing production records, and whatever other actions are appropriate to determine if adulterated, illegal products are being sold. If such a determination is made, the FDA should immediately take appropriate enforcement action."