Monday, March 21, 2011

Grapefruit Seed Extract Q & A

Grapefruit seed extract (GSE) is an item commonly available in health food stores and a commonly held perception is that the product is “natural.” However, as it turns out, the “natural” designation may be inaccurate. The study “Identification of Benzethonium Chloride in Commercial Grapefruit Seed Extracts” (Takeoka, Dao, Wong, Lundin, Mahoney, 2001) states “the composition of commercial GSE is not defined, and its methods of production are proprietary and not specified,”[1] which leaves some question about its safety for internal use.

Several studies have found part of the “proprietary” ingredients include potentially harmful preservatives. In fact, to our knowledge, no authenticated GSE has been found to be free of preservatives; therefore, it is unclear if tested GSE has been found effective because of the effects of preservative ingredients, such as benzethonium chloride, methylparaben, and triclosan.

Each of these ingredients—benzethonium chloride, methylparaben, and triclosan— has a profile on the Skin Deep Cosmetic Safety Database and we encourage you to conduct some personal research into their potential effects on the body. (Skin Deep is a personal care safety guide compiled by researchers at the nonprofit Environmental Working Group.)

For example, the Skin Deep Cosmetic Safety Database links benzethonium chloride with potential cancer risks and moderate risk for neurotoxicity and organ system toxicity[2]. Similarly, methylparaben and triclosan have both been linked to cancer, as well as endocrine disruption[3] and potential skin, eye, and lung irritation[4].

The Environmental Protection Agency (EPA) triclosan fact sheet lists triclosan as an antimicrobial pesticide used commercially, industrially, residentially, and as a materials preservative included in items like hand soaps, toothpastes, adhesives, fabrics, and carpeting[5].

However, triclosan is a potential endocrine disruptor in humans. A 2006 study (Veldhoen et al.), “investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog,” and found low levels of exposure to triclosan disrupted thyroid hormone-associated gene expression, potentially altering “the rate of thyroid hormone-mediated postembryonic anuran development”[6].

In addition, triclosan has been found to inhibit photosynthesis in diatom algae, a major group of algae that contributes much of the photosynthetic activity necessary for a healthy ecosystem.[7] Through photosynthesis, diatom produce food and oxygen for other organisms, contributing “an estimated 80 percent of the oxygen in our atmosphere, making them essential to life on earth” (Beyond Pesticides, 2010)[8]. This of special concern when you consider triclosan may remain in the environment for 30 or more years[9].

Read the full-length article "Health Benefits of Grapefruit Seed Extract: Follow Up Q & A" from the March 2011 edition of ACHS' The Reporter online here.

[1] Takeoka, G., Dao, L., Wong, R., Lundin, R., Mahoney, N. (2001). Identification of Benzethonium Chloride in Commercial Grapefruit Seed Extracts. J. Agric. Food Chem. 49, 3316-3320.
[2] Skin Deep Cosmetic Safety Database. (2011). BENZETHONIUM CHLORIDE. Retrieved from
[3] Skin Deep Cosmetic Safety Database. (2011). METHYLPARABEN. Retrieved from
[4] Skin Deep Cosmetic Safety Database. (2011). TRICLOSAN. Retrieved from
[5] Environmental Protection Agency. (2011, February 16). Triclosan Facts. Retrieved from
[6] Veldhoen, N., Skirrow, R., Osachoff, H., Wigmore, H., Clapson, D., Gunderson, M., et al. (2006). The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development. Aquatic Toxicology 80(3,1), 217-227. Abstract obtained from
[7] Ricart, M., Guasch, H., Alberch, M., et al. (2010). Triclosan persistence through wastewater treatment plants and its potential toxic effects on river biofilms. Aquat. Toxicol. 100 (4): 346–53. Abstract retrieved from
[8] Beyond Pesticides Daily News Blog. (2010, November 15). Triclosan in Waterways Harmful to Important Microorganisms. Retrieved from
[9] Singer, H., Muller, S., Tixier, C., Pillonel, L. (2002). Triclosan: occurrence and fate of a widely used biocide in the aquatic environment: field measurements in wastewater treatment plants, surface waters, and lake sediments. Environ Sci Technol 1;36(23):4998-5004. Abstract retrieved from

1 comment:

S. Waters said...

Thank you for posting this. (The Cosmetics Database is fantastic, too!)