Why we don't sell grapefruit seed extract.
July 21, 2005
Subject: Grapefruit seed extract may owe its antimicrobial action to toxic
The widespread promotion and usage of grapefruit seed extract (GSE) within
the health food industry and its promotion by practitioners of alternative
medicine is a matter of concern to me. We stopped selling it a number
of years ago. I want to explain why.
The problem is that it works, just like the company's promotional literature
says it does, but for all the wrong reasons. The germ killing properties
of commercial GSE do not come from any chemical within grapefruit seeds
but to chemical additives that are slipped in during manufacture.
I have reports going back over ten years in which chemical analysis of
GSE found methyl-p-hydroxybenzoate and triclosan. in the products
These two chemicals are preservatives. Other studies which have
analyzed GSE have found benzethonium chloride and methyl parabene. None
of these chemicals occur naturally in grapefruit seeds. It wasn't
a surprise then when these reports were confirmed by published research.
In 1999 German scientists evaluated six commercial preparations of grapefruit
seed extract and tested their antimicrobial properties. Five of
the six extracts showed a strong inhibitory effect. In all five
of the extracts which 'worked' they found the bensethonium chloride, a
preservative. Three of the extracts contained triclosan and methyl
parabene. The one extract with no antimicrobial activity had no
preservative agents added. A 'homemade' extract which the researchers
prepared had no antimicrobial activity. The researchers concluded
that the potent and nearly universal antimicrobial activity attributed
to grapefruit seed extract is due to synthetic preservatives added and
not due to the actual extract.
What is a surprise is that this information hasn't slowed sales of these
products or that the health food industry feels no need to dump these
products off their collective shelves for fraud and misrepresentation.
Benzethonium chloride is a disinfectant commonly used in cosmetics and
is categorized as a class 2 poison because of its teratogenicity and caustic
effects. Upwards of 8% has been found in GSE products, far more
than ever used in cosmetics. The Environmental Defense Fund describes
this chemical as a "suspected endocrine toxicant." According to the National
Institute for Occupational Health and Safety, taking benzethonium chloride
internally could cause, " diarrhea, nausea, vomiting, collapse, convulsions
(and) coma." This chemical and by extension, grapefruit seed extract
is a potentially harmful compound and is not approved for internal use.
Triclosan isn't much better. The EPA lists it as a pesticide and
although widely used in cosmetics is not approved for internal use.
Of late I have received a great many communications from the health food
industry and from 'public advocates' decrying attempts by the FDA and
other regulatory bodies to oversee the sale of supplements and other natural
products. It is hard to hear the merit of these arguments when we
see such egregious conduct as the continuing promotion and sale of products
like Grapefruit Seed Extract.
Pharmazie. 1999 Jun;54(6):452-6.
Aspects of the antimicrobial efficacy of grapefruit seed extract and its
relation to preservative substances contained.
von Woedtke T, Schluter B, Pflegel P, Lindequist U, Julich WD.
Institute of Pharmacy, Ernst Moritz Arndt University, Greifswald, Germany.
The antimicrobial efficacy as well as the content of preservative agents
of six commercially available grapefruit seed extracts were examined.
Five of the six extracts showed a high growth inhibiting activity against
the test germs Bacillus subtilis SBUG 14, Micrococcus flavus SBUG 16,
Staphylococcus aureus SBUG 11, Serratia marcescens SBUG 9, Escherichia
coli SBUG 17, Proteus mirabilis SBUG 47, and Candida maltosa SBUG 700.
In all of the antimicrobial active grapefruit seed extracts, the preservative
benzethonium chloride was detected by thin layer chromatography. Additionally,
three extracts contained the preserving substances triclosan and methyl
parabene. In only one of the grapefruit seed extracts tested no preservative
agent was found. However, with this extract as well as with several self-made
extracts from seed and juiceless pulp of grapefruits (Citrus paradisi)
no antimicrobial activity could be detected (standard serial broth dilution
assay, agar diffusion test). T
is concluded that the potent as well as nearly universal antimicrobial
activity being attributed to grapefruit seed extract is merely due to
the synthetic preservative agents contained within. Natural products with
antimicrobial activity do not appear to be present.
We hope you find the information in these newsletters useful, informative
and hopefully entertaining. If you want your name removed simply leave
a message at the office (303-337-4884) or go to the website: denvernaturopathic.com
and unsubscribe, or reply with the message "REMOVE" in the subject line.
If on the other hand you want to be added to the mailing list follow the
prior instructions but subscribe.
We are posting most of these newsletters in our 'NEWS' section of the
website. The website versions contain more complete references and
often abstracts of the references quoted and links to the full text of
many of the journal articles mentioned. You don't have to be a patient
to sign up and we encourage you to get your friends on our mailing list
so you don't have to keep forwarding the newsletters that you find interesting.