Supplement closet skeleton grapefruit seed extract makes appearance in warning letter

By Hank Schultz

- Last updated on GMT

©Getty Images - Ildo Frazao
©Getty Images - Ildo Frazao

Related tags regulations Adulteration Adulterant

Grapefruit seed extract, a dubious ingredient that seems to have more lives than a cat, has made another official appearance, this time in a warning letter from the US Food and Drug Administration.

The warning letter, dated Oct. 22, 2021 and posted Feb. 1, 2022, is addressed to a company called Applied Health Solutions, based in Scottsdale, AZ.  The warning letter, which like many such letters during the pandemic, arose from a review of the company’s website as opposed to a physical inspection of the company’s premises.

As such, the letter focuses entirely on disease claims​, as opposed to citing any GMP compliance problems.  Under the Applied health Sciences name the company markets a variety of supplements and has a line of grapefruit seed extracts under the Nutribiotic brand name.

According to the warning letter, the company allegedly has been making a wide variety of disease claims on its products.  The warning letter alleged that claims such as anti cancer activity and ability to fight respiratory and gut infections.

Claims of fighting MRSA

For the grapefruit seed extract products, the company allegedly was making claims that the products could MRSA (Methicillin-resistant Staphylococcus aureus)​ infections as well as fight against AIDS, Candida and other infections.

It’s not the first time that a grapefruit seed extract has been claimed to have antimicrobial properties, and it’s unlikely to be the last.  However, according to the American Botanical Council and other authorities, there is virtually no evidence in the botanical literature for this claim.

Synthetic antimicrobial components

Whatever antimicrobial properties that these products might have demonstrated in the past has been due to the inclusion of commercial antimicrobial products, some of which may even not have been originally intended for internal use. 

There are a variety of grapefruit seed extract products on the market, some of which claim to be extracts of the plant’s seeds, rind and fruit.  Most of these claim a generalized digestive health benefit.  Even this claim has little support in the literature. This seems to be a case of putting products on the market because there is a certain consumer base looking for them, not because they have any demonstrated activity.

“I’m sure there are authentic grapefruit seed extracts on the market,”​ said Stefan Gafner, PhD, chief science officer of ABC and head of the Botanical Adulterants Prevention Program. “But if they are truly authentic whatever antimicrobial activity would be very, very limited.”

Recent study used uncharacterized material

There was a study published last year that purported to find an effect of grapefruit seed extract on MSRA.  The study, done by South Korean researchers, claimed that, “In this study, 12 plant extracts known for having antibacterial activity were analyzed by disk diffusion test against MSSA. From this screening test, only GSE showed antibacterial effect.“ 

But it went on to include this curious statement, that the specifications of the grapefruit seed extract were “unrevealed due to the company’s confidentiality.”​  ​It’s odd that the researchers would use a poorly characterized material when the provenance of that particular ingredient has been questioned by so many within the industry and for so many years.

The ongoing controversy about grapefruit seed extract led BAPP to put out a lab guidance document​ to allow companies to figure out what kind fo synthetic antimicrobial constituents might be in there.  In addition, ABC has been advocating for the acronym GFSE to be used, to distinguish these most likely fraudulent materials from grapeseed extracts (GSE), which do have a wealth of clinical data backing  their use and bioactivity.

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