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Grapefruit seed extracts

The Schleswig-Holstein problem was thought to be understood by three people, two of whom were mad. Similar mind-bending problems not amenable to simple souls crop up in medicine. They occur particularly in the field of alternative and complementary therapy. As an example, Bandolier introduces the grapefruit seed extract problem.

Grapefruit seed extracts

The BBC health site has an "Ask the doctor" section. One question was about Candida and grapefruit seed extract. Dr Trisha Macnair said that she could find no evidence that it had any therapeutic effect, and suggested seeing a complementary therapist. That is the grapefruit seed extract problem in a nutshell - we can't find evidence that it works.

But hang on a moment. That doesn't mean there is no evidence. Analysis of six commercial grapefruit seed extracts [1] showed five had antimicrobial properties, and were active against a strain of Candida. In all extracts with antimicrobial activity the chemical benzethonium was found, and, in some, triclosan and methyl parabene. The only extract without antimicrobial activity contained no chemicals. The chemicals detected are those used to preserve grapefruit. The only antimicrobial property came from synthetic chemicals. Organic grapefruit would have no effect.


Bandolier will have its comprehensive alternative therapy website ready in a few months. We have identified about 100 systematic reviews, but need to know what questions you have about "alternatives" - your grapefruit seed extract problem. Questions you want answered, please, by email ( ) or fax (+44 1865 226978).

  1. von Woedtke et al. Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained. Pharmazie 1999 54: 452-456.

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