Grapefruit seed extract
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Grapefruit seed extract (GSE), also known as citrus seed extract, is a liquid derived from the seeds, pulp, and white membranes of grapefruit. While there has been no scientific demonstration of efficacy, this extract has been alleged by some practitioners of alternative medicine to possess antibacterial, antiviral, and anti-fungal properties. Indeed, it has been recommended by some nutritionists for the treatment of candidiasis, earache, throat infections, and diarrhea. Some natural food retailers claim this extract to be safe, natural, and effective. However, recent studies have identified synthetic preservatives in commercial grapefruit seed extracts. When no preservatives were present in some of the extracts tested in the laboratory, the natural extracts were found to have little or no natural antimicrobial attributes of their own. An early proponent was Dr. Jacob Harich (1919–1996). Some of the manufacturers of GSE have claimed that their extract has compounds nearly identical to benzethonium chloride but the 2001 study overiewed by chemist G. Takeoka and ran by fellow researchers have documented that commercial GSE preparations contain the synthetic compound benzethonium chloride that couldn't have been made from GSE. Yet, promoters from book authors to cosmetic companies still affirm this extract has strong natural healing properties even though the validity of the studies portray the opposite.
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[edit] Scientific research
Anecdotal claims for an antimicrobial effect are loosely supported by small abstract experiments which apparently show some antimicrobial activity in in vitro assays such as the agar diffusion test.<ref>Reagor L, Gusman J, McCoy L, Carino E, Heggers JP. The effectiveness of processed grapefruit-seed extract as an antibacterial agent: I. An in vitro agar assay. J Altern Complement Med. 2002 Jun;8(3):325-32. Grapefruit Seed Extract (GSE) Brand Test Study</ref><ref>Cvetnic Z, Vladimir-Knezevic S. Antimicrobial activity of grapefruit seed and pulp ethanolic extract. Acta Pharm. 2004 Sep;54(3):243-5. In Vitro Agar Assay Brand Test</ref><ref>Heggers JP, Cottingham J, Gusman J, Reagor L, McCoy L, Carino E, Cox R, Zhao JG. The effectiveness of processed grapefruit-seed extract as an antibacterial agent: II. Mechanism of action and in vitro toxicity. J Altern Complement Med 2002 Aug;8(4):521. Reagor Lana, corrected to Reagor Lee. Preservative Brand Name Test Study</ref> However, there is considerable scientific evidence that the anti-microbial activity associated with grapefruit seed extract is attributable to the contamination or adulteration of commercial GSE preparations with synthetic antimicrobials or preservatives.<ref name=Preservatives>Ganzera M, Aberham A, Stuppner H. Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract. Institute of Pharmacy, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria. J Agric Food Chem. 2006 May 31;54(11):3768-72. Abstract</ref> After careful evaluation of the anecdotal claims for an antimicrobial effect, the preliminary studies state that the Citricidal brand of GSE was used for testing. That said, despite the anecdotal antimicrobial claims, according to the 2001 GSE study, the Citricidal brand as well as the Nutribiotic brand were both contaminated with synthetic benzethonium chloride that was implausible to be made from grapefruit seeds.<ref name=Contamination>Takeoka, G., Dao, L., Wong, R.Y., Lundin, R., Mahoney N. Identification of benzethonium chloride in commercial grapefruit seed extracts. J Agric Food Chem. 2001 49(7):3316–20. Abstract</ref>
Independent studies have shown that commercial preparations contain the compound benzalkonium chloride, which is a synthetic antimicrobial commonly used in disinfectants and cleaning products, the related compound benzethonium chloride, the antibiotic triclosan, or the preservative methylparaben.<ref name=Pharmazie>von Woedtke, T., Schlüter, B., Pflegel, P., Lindequist, U.; Jülich, W.-D. Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained. Pharmazie 1999 54:452–456. Abstract</ref><ref name=Study>Sakamoto, S., Sato, K., Maitani, T., Yamada, T. Analysis of components in natural food additive “grapefruit seed extract” by HPLC and LC/MS. Bull. Natl. Inst. Health Sci. 1996, 114:38–42. Abstract</ref><ref name=Adulteration>Takeoka, G.R., Dao, L.T., Wong, R.Y., Harden L.A. Identification of benzalkonium chloride in commercial grapefruit seed extracts. J Agric Food Chem. 2005 53(19):7630–6. Abstract</ref> Some samples were shown to contain up to 22% benzalkonium chloride by weight, despite the known allergenicity and toxicity of the compound at higher doses.<ref name=Adulteration/> These chemicals were not present in grapefruit seed extracts prepared in the laboratory, and GSE preparations without the contaminants were found to possess no significant antimicrobial effect.<ref name=Pharmazie/> Self-made citrus seed extracts had no broad-spectrum capabilities as a preservative. Although GSE is sold in health food shops, there is no good evidence for any natural antimicrobial activity.
A study that examined the antiviral properties of GSE found that GSE had no efficacy as a disinfectant for feline calicivirus and feline parvovirus.<ref>Eleraky, N.Z., Potgieter, L.N., Kennedy, M.A. Virucidal efficacy of four new disinfectants. J Am Anim Hosp Assoc. 2002 38(3):231–4. Abstract</ref> Grapefruit seed extract has been advocated to be a powerful antimicrobial with proven activity against bacteria and fungi. However, independent studies have shown the efficacy of grapefruit seed extract as an antimicrobial is not demonstrated. Although citrus seed extract is claimed to be a highly effective plant-based preservative by some natural personal care manufacturers, studies scientifically indicate the universal antimicrobial benefits associated with GSE are merely from the presence of synthetic preservatives. Natural GSE has no antimicrobial properties.
[edit] Precautions
Consequential to the identification of preservatives in commercial GSE which are sold at some natural food markets, people who are sensitive to eating synthetic preservatives may exercise caution in administering GSE at any dilution to prevent an allergic reaction.
Grapefruit can have a number of interactions with certain drugs, increasing the potency of many compounds. Grapefruit has components that inhibit the production of a particular enzyme in the liver. Thus, it is this effect that increases the rate of absorption of several drugs.<ref>He K; Iyer KR; Hayes RN; Sinz MW; Woolf TF; Hollenberg PF. Inactivation of cytochrome P450 3A4 by bergamottin, a component of grapefruit juice. Chem Res Toxicol. 1998 Apr;11(4):252-9. Abstract</ref>
[edit] GSE controversy
GSE usage has been popularized by many companies within the scope of the health food industry. There are books exclusively dedicated to GSE.<ref>Sharamon, S., Baginski, B.J. The Healing Power of Grapefruit Seed. Lotus Press, Wisconsin. 1996. ISBN 0-914955-27-6</ref><ref>Sachs, A. The Authoritative Guide to Grapefruit Seed Extract : Stay Healthy Naturally: A Natural Alternative for Treating Colds, Infections, Herpes, Candida and Many Other Ailments. LifeRhythm, Medocino, California, 1997. ISBN 0-940795-17-5</ref><ref>Sims, Judith. Gale Encyclopedia of Alternative Medicine. Available in e-book format. Thomson Gale. 2001.</ref> This extract is promoted by marketers on the internet. Some health food stores continue to recommend it. Some consumers believe this extract is an effective natural preservative despite the findings of multiple scientific studies have concluded the universal antimicrobial activity is merely from contamination with synthetic antimicrobials.<ref name=Preservatives/><ref name=Contamination/><ref name=Pharmazie/><ref name=Study/><ref name=Adulteration/>
[edit] References
[edit] See also
Read the quackery article for an explanation as to why products like citrus seed extract persists in usage and is accepted by some consumers in spite of its lack of effectiveness.
Read the charlatan article for reasoning as why a salesperson or business would want to practice quackery or similar confidence trick under false pretences.
