Grapefruit seed extract
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2008-04-12T03:17:55Z
AubreyinFlorida
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'''Grapefruit seed extract''' (GSE), also known as '''citrus seed extract''', is a liquid derived from the [[seed|seeds]], [[citrus#uses|pulp]], and white membranes of [[grapefruit]]. While there has been no scientific demonstration of efficacy, this [[herbal extract|extract]] has been claimed by some practitioners of [[alternative medicine]] to possess [[antiseptic|antibacterial]], [[antiviral drug|antiviral]], and [[antifungal drug|anti-fungal]] properties. Indeed, it has been recommended by some [[nutritionist|nutritionists]] for the treatment of [[candidiasis]], [[otalgia|earache]], throat infections, and [[diarrhea]]. Some natural food retailers claim this extract to be a safe, natural, and an effective preservative. Recent studies have identified synthetic preservatives in commercial grapefruit seed extracts. When preservatives were not present in some of the extracts, laboratory tests found the natural extracts 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 a [[2001]] [[research|study]] overviewed by [[chemist]] G. Takeoka and run by fellow researchers has documented that commercial GSE preparations contain the [[Chemical synthesis|synthetic]] compound benzethonium chloride that couldn't have been made from GSE. Nonetheless, promoters from book authors to cosmetic companies continue to affirm that citrus seed extract has strong natural healing properties despite lack of scientific or clinical evidence.
== History ==
The grapefruit is a sub-tropical [[citrus]] [[tree]] grown for its [[fruit]] which was originally named the "forbidden fruit" of Barbados.<ref name="Forbidden_Fruit">Morton, J. 1987. Grapefruit. p. 152–158. In: Fruits of warm climates. Julia F. Morton, Miami, FL. [http://www.hort.purdue.edu/newcrop/morton/grapefruit.html Forbidden Fruit Reference]</ref> The fruit was first documented in [[1750]] by Rev. Griffith Hughes describing specimens from [[Barbados]].<ref name="Q_A:Grapefruit">World Wide Words: Questions & Answers; Grapefruit. [http://www.worldwidewords.org/qa/qa-gra3.htm Abstract]</ref> All parts of the fruit have uses. The fruit is mainly consumed for a tangy [[juice]].<ref name="Citrus_Juice">Fellers PJ, Nikdel S, Lee HS. Nutrient content and nutrition labeling of several processed Florida citrus juice products. ''J Am Diet Assoc.'' 1990 Aug;'''90'''(8):1079-84. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2380455 Abstract]</ref> The peel is expressed into an [[aromatherapy]] [[essential oil|oil]]<ref name="Valerie">Ann Worwood, Valerie. The Complete Book of Essential Oils and Aromatherapy (Paperback). ''New World Library'' 1991. ISBN 0-93143-282-0</ref> and is also a source of dietary [[pectin|fiber]].<ref name="Pectin_Benefits">Cerda JJ, Robbins FL, Burgin CW, Baumgartner TG, Rice RW. The effects of grapefruit pectin on patients at risk for coronary heart disease without altering diet or lifestyle. ''Clin Cardiol.'' 1988 Sep;'''11'''(9):589-94. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3229016 Abstract]</ref> The seed and pulp as a by-product of the juice industry is sold as cattle feed<ref name="Cattle_Feed">Arthington JD, Kunkle WE, Martin AM. Citrus pulp for cattle. ''Vet Clin North Am Food Anim Pract.'' 2002 Jul;'''18'''(2):317-26, vii. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12235663 Abstract]</ref> and is manufactured for use to make an extract.<ref name="Pharmazie"/> GSE was originally developed by Dr. Jacob Harich, a nuclear physicist. In 1963, he journeyed to Florida, the [[heart (symbol)|heart]] of grapefruit country, and began researching and later [[marketing#definitions|marketing]] of GSE.<ref name="E-Book"/> Today, GSE is mostly promoted at [[health food store|health food shops]] and on the [[internet#marketing|internet]].<ref name="Adulteration"/>
== Scientific research ==
Anecdotal claims for an antimicrobial effect are loosely supported by small abstract scientific experiments which apparently show some antimicrobial activity in ''[[in vitro]]'' assays such as the [[agar diffusion test]].<ref name=BrandStudy>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. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12165190&query_hl=1 Grapefruit Seed Extract (GSE) Brand Test Study]</ref><ref name="BrandTest">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. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12165191&query_hl=1 Preservative Brand Name Test Study]</ref><ref name="EthanolGSE">Cvetnic Z, Vladimir-Knezevic S. Antimicrobial activity of grapefruit seed and pulp ethanolic extract. ''Acta Pharm.'' 2004 Sep;'''54'''(3):243-5. [http://pubwww.srce.hr/acphee/24304.pdf Full Text] [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15610620&query_hl=1 Abstract]</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. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16719494 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.<ref name="BrandStudy"/><ref name="BrandTest"/> 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 RY, Lundin R, Mahoney N. Identification of benzethonium chloride in commercial grapefruit seed extracts. ''J Agric Food Chem.'' 2001 '''49'''(7):3316–20. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11453769 Abstract]</ref> Another ''in vitro study'' claimed GSE had antibacterial properties.<ref name=EthanolGSE/> As with the branded in vitro test<ref name="BrandStudy"/><ref name="BrandTest"/> this extract was contaminated.<ref name="Contamination"/> The ethanolic extract tested had become contaminated with ethanol, a chemical used in the extraction process.<ref name="EthanolGSE"/> [[Ethanol]], also known as ethyl alcohol, is effective in inhibiting bacteria.<ref name="Ethanol_Alcohol_Effectiveness">Kampf G, Kramer A. Epidemiologic background of hand hygiene and evaluation of the most important agents for scrubs and rubs. Bode Chemie GmbH & Co., Scientific Affairs, Melanchthonstrasse 27, 22525 Hamburg, Germany. ''Clin Microbiol Rev.'' 2004 Oct;'''17'''(4):863-93. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15489352 Abstract]</ref> Nevertheless, as a result of marketing by manufacturers in the health food arena and a few misinterpreted studies conducted in vitro that tested contaminated extracts which were not pure GSE processed without solvents or brands which are known to contain preservatives, the [[controversy]] over the effectiveness of GSE continues even when studies conclude – self-made pure GSE has no natural antimicrobial properties and commercial GSE has been identified with contamination from synthetic preservatives.<ref name="Pharmazie"/><ref name="Adulteration"/><ref name="Preservatives"/><ref name="Contamination"/><ref name="Study"/>
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 [[paraben|methylparaben]].<ref name="Pharmazie">von Woedtke T, Schluter B, Pflegel P, Lindequist U, Julich WD. Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained. ''Pharmazie'' 1999 '''54''':452–456. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10399191&query_hl=1 Abstract]</ref><ref name="Adulteration">Takeoka GR, Dao LT, Wong RY, Harden LA. Identification of benzalkonium chloride in commercial grapefruit seed extracts. ''J Agric Food Chem.'' 2005 '''53'''(19):7630–6. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16159196&query_hl=1 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. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9037863&query_hl=1 Abstract]</ref> Some samples were shown to contain up to 22% benzalkonium chloride by weight, despite the known [[allergy|allergenicity]]<ref name="Alergenicity">Chiambaretta F, Pouliquen P, Rigal D. Allergy and preservatives. Apropos of 3 cases of allergy to benzalkonium chloride. ''J Fr Ophtalmol.'' 1997;'''20'''(1):8-16. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9099278 Abstract]</ref> and [[toxicity]]<ref name="Toxicity">Liu H, Routley I, Teichmann KD. Toxic endothelial cell destruction from intraocular benzalkonium chloride. ''J Cataract Refract Surg.'' 2001 Nov;'''27'''(11):1746-50. Comment in: ''J Cataract Refract Surg.'' 2003 Feb;'''29'''(2):233.
[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11709246 Abstract]</ref> 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 markets,<ref name="Adulteration"/> there is no good evidence for any natural antimicrobial activity.<ref name="Pharmazie"/>
A study that examined the antiviral properties of GSE found that GSE had no efficacy as a disinfectant for [[feline calicivirus]] and [[feline panleukopenia|feline parvovirus]].<ref name="Virucidal_Efficacy">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. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12022408&query_hl=19 Abstract]</ref>
Grapefruit seed extract has been advocated to be a powerful [[antimicrobial]] with proven activity against [[bacteria]] and [[fungus|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 skin care|natural personal care manufacturers]], studies asserted that the universal antimicrobial benefits associated with GSE are merely from the presence of synthetic [[preservative|preservatives]]. [[Nature|Natural]] GSE has no antimicrobial properties.<ref name="Pharmazie"/><ref name="Preservatives"/>
== Properties ==
There is good evidence that the extract of citrus grapefruit seed has low levels of [[antioxidant]] properties.<ref name="Extract">Armando, C., Maythe, S., Beatriz, N. P. Antioxidant activity of grapefruit seed extract on vegetable oils. ''Journal of the Science of Food and Agriculture'' 1997 Dec;'''77'''(4):463-467. [http://www3.interscience.wiley.com/cgi-bin/abstract/10007270/ABSTRACT Abstract]</ref><ref name="Antioxidant_Activity">Giamperi L, Fraternale D, Bucchini A, Ricci D. Antioxidant activity of Citrus paradisi seeds glyceric extract. ''Fitoterapia.'' 2004 Mar;'''75'''(2):221-4. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15030930 Abstract]</ref>
Analysis shows the constituents of the seed extract and pulp are [[flavonoids]],<ref name="Drewnowski">A. Drewnowski and C. Gomez-Carneors, Bitter taste, phytonutrients, and consumer: a review, ''Am. J. Clin. Ntr.'' '''72'''(2000) 1424-1435.</ref><ref name="Tirillini">B. Tirillini, Grapefruit: the last decade acquisitions, ''Fitoterapia'' '''71'''(2000) 29-37.</ref> [[ascorbic acid]] (commonly known as [[vitamin C]]<ref name="Vitamin_C">Andrew W. Saul, Ph.D. Vitamin C Has Been Known To Fight 30 Major Diseases... For Over 50 Years. ''Orthomolecular Medicine News Service.'' March 15, 2006. [http://www.orthomolecular.org/resources/omns/v02n02.shtml Article]</ref><ref name="ACS_C">Vitamin C. ''American Cancer Society.'' [http://www.cancer.org/docroot/ETO/content/ETO_5_3X_Vitamin_C.asp?sitearea=ETO Article]</ref><ref name="WHF">The World's Healthiest Foods; Grapefruit. ''The George Mateljan Foundation.'' [http://www.whfoods.com/genpage.php?tname=foodspice&dbid=25 Article]</ref>), [[tocopherol|tocopherols]], [[citric acid]],<ref name="Extract"/> [[limonoid|limonoids]],<ref name="Glucosides_Of_Acidic_Limonoids">R. D. Bennett, S. Hasegava and Z. Herman, Glucosides of acidic limonoids in citrus, ''Phytochemistry'' '''28'''(1989) 2777-2781.</ref><ref name="Limonoide_Glucosides">H. Ohta, C. H. Fong, M. Berhow and Hesegawa, Thin-layer and high-performance liquid chromatographic analyses of limonoids and limonoid glucosides in citrus seeds, ''J. Chromatogr.'' '''639'''(1993) 295-302.</ref><ref name="Braddock">R. J. Braddock and C. R. Bryan, Extraction parameters and capillary electrophorisis analysis of limonin glucoside and phlorin in citrus products, ''J. Agric. Food Chem.'' '''49'''(2001) 5982-5988.</ref> [[sterols]], and [[minerals]].<ref name=Tushiswilli">L. Sh. Tushiswili, S. V. Durmishidze and K. V. Sulaberidze. Sterols of grapefruit, orange, mandarin pulps (''Citrus paradisi, Citrus sinensis, Citrus unshiu''), ''Chem. Nat. Comp.'' '''18'''(1983) 445-447.</ref> A study suggests the consumption of the bioactive compounds found in grapefruit seed and pulp may help suppress the development colon cancer.<ref name="Vanamala">Vanamala J, Leonardi T, Patil BS, Taddeo SS, Murphy ME, Pike LM, Chapkin RS, Lupton JR, Turner ND. Suppression of colon carcinogenesis by bioactive compounds in grapefruit. Department of Nutrition and Food Science, Texas A&M University, College Station, TX 77843, USA. ''Carcinogenesis.'' 2006 Jun;'''27'''(6):1257-65. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16387741 Abstract]</ref> Another study showed the [[flavonoid]] naringin is an excellent plasma lipid lowering and plasma antioxidant active elevating flavonone.<ref name="Naringin">Gorinstein S, Leontowicz H, Leontowicz M, Krzeminski R, Gralak M, Delgado-Licon E, Martinez Ayala AL, Katrich E, Trakhtenberg S. Changes in plasma lipid and antioxidant activity in rats as a result of naringin and red grapefruit supplementation. ''J Agric Food Chem.'' 2005 Apr 20;'''53'''(8):3223-8. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15826081 Abstract]</ref>
== Preparations ==
Self-made pure GSE processed without solvents is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin.<ref name="Pharmazie"/>
Commercially available GSE sold to consumers are made from the seed, pulp, glycerin, and synthetic preservatives all blended together.<ref name="Pharmazie"/>
== Precautions ==
As synthetic preservatives have been found in commercial GSE preparations, people who are sensitive to eating synthetic preservatives should exercise caution in administering GSE at any dilution to prevent an [[hypersensitivity|allergic reaction]].<ref name="Preservative_Hypersensitivity">Sasseville, Denis. Hypersensitivity to preservatives. ''Dermatologic Therapy. ''2004;'''17'''(3):251-63. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15186371 Abstract]</ref>
Grapefruit can have a [[List of drugs affected by grapefruit|number of interactions]] with certain [[drug|drugs]], increasing the potency of many compounds, including [[warfarin]] (coumadin). Grapefruit has components that inhibit the CYP3A4 enzyme in the intestine.<ref name="NYTimes">Bakalar, Nicholas. Experts Reveal the Secret Powers of Grapefruit Juice. ''New York Times.'' Published: March 21, 2006. [http://www.nytimes.com/2006/03/21/health/21grap.html?ex=1300597200&en=61e834f36b9afac9&ei=5090&partner=rssuserland&emc=rss Article]</ref> Thus, it is this effect that increases the rate of absorption of several drugs.<ref name="GSE_Drug_Effect">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. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9548795&dopt=Abstract Abstract]</ref>
== 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 name="E-Book">Sims, Judith. Gale Encyclopedia of Alternative Medicine. Available in e-book format. ''Thomson Gale.'' 2001.</ref><ref name="Healing_Powers">Sharamon, S., Baginski, B.J. The Healing Power of Grapefruit Seed. ''Lotus Press, Wisconsin.'' 1996. ISBN 0-914955-27-6</ref><ref name="GSE_Guide">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> 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="Pharmazie"/><ref name="Adulteration"/><ref name="Preservatives"/><ref name="Contamination"/><ref name="Study"/><ref name="artificial_grapefruit_seed_extract">Brandin H, Myrberg O, Rundlöf T, Arvidsson AK, Brenning G. Adverse effects by artificial grapefruit seed extract products in patients on warfarin therapy. ''Eur J Clin Pharmacol.'' 2007 Jun;'''63'''(6):565-70. [http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=17468864 Abstract]</ref>
== See also ==
* [[Extract]]
== References ==
{{reflist}}
== External links ==
*[http://www.wellvet.com/grapefruitseedextracts.html WellVet Company -- Grapefruit Seed Extract: Articles, Conclusions, and References.]
*[http://www.spectroscopynow.com/coi/cda/detail.cda?chId=4&id=13654&type=Feature&page=1 Ecofriendly Pesticides Are Not What They Seem -- Article by Steve Down; June 1, 2006.]
*[http://www.senescence.info/causes.html Damage-Based Theories of Aging -- Free Radical Theory of Aging: Role of Antioxidants in Aging.]
[[Category:Antioxidants]]
[[Category:Grapefruit]]
[[Category:Scientific skepticism]]