GSE : Beware – This “Natural” Antibiotic Doesn’t Work
Imagine an all-natural, fruit-based product that’s powerful enough to kill bacteria, viruses, and other harmful substances, yet gentle enough to use internally or topically.
Sounds great, right?
But now imagine the product turns out not to be as natural as you thought. In fact, it’s filled with synthetic additives and preservatives that may be the real reason for its supposed benefits.
And, despite rave reviews from proponents who say it can cure everything from acne to cancer, let’s say there was no good scientific evidence to support these claims.
Would you still be interested in this remedy?
A Fruitful Germ Killer?
A bitter liquid derived from the seeds, pulp, and membranes of this citrus fruit, grapefruit seed extract (GSE) didn’t come to researchers’ attention until the 1960s. But even when it did, it wasn’t studied for human health: In fact, GSE was valued for its ability to protect fruits and vegetables against parasites, fungi, and bacteria.
Nonetheless, GSE began to develop a reputation as a potent germ killer over the years – not just for produce, but for people, too. By the 1990s, alternative practitioners had begun touting its alleged health benefits and recommending it as a home remedy for a slew of problems, from mild gastrointestinal complaints to cancer.
So does GSE really work?
That’s the million-dollar question.
See, laboratory research does suggest that GSE contains compounds that appear to protect against a broad spectrum of bacteria, including salmonella, staphylococcus, streptococcus, and E. coli, as well as many types of fungus and yeast and some parasites. Though, as I will discuss in a moment, the real reason GSE protects against these germs may have nothing to do with its natural constituents.
GSE has also been shown to be rich in an antioxidant flavonoid called naringenin, which improves blood flow, as well as other flavonoids, carotenoids, and pectin.
You can see why some people are excited about GSE’s potential health effects.
But the answers aren’t so clear-cut.
There’s no shortage of claims for GSE products. Some proponents believe that GSE can benefit weight loss and skin complexion. Others extol benefits ranging from treatment for gastrointestinal problems to a “miracle cancer cure.”
But here’s the problem: There’s little evidence to support any of these promises.
Sure, it’s true that there’s some preliminary research on GSE and human health. For example, one 1990 found that daily treatment for a month with liquid GSE or capsules helped improve symptoms in people with irritable bowel syndrome. However, no further studies have found similar results.
A few animal studies suggest that GSE might lower blood pressure, blood sugar, and cholesterol in rats – but it’s a long way from mice to men.1,2
Overall, despite some initial promising lab studies that suggest some benefits for GSE, the clinical research is still lacking.
Not So Natural…
In light of the fact that more research is needed, you may wonder if it’s worth giving GSE a shot.
The answer is “maybe” – but only if you don’t care that this “natural” product may NOT be totally natural.
See, recent studies have identified synthetic preservatives in commercial grapefruit seed extracts.4,5,6
For instance, a 2006 study found that seven out of nine GSE samples contained synthetic chemicals including benzethonium chloride, benzoic acid, and benzalkonium chloride. Worse, the authors of this study found that any antibacterial activity attributed to GSE is actually due to the presence of these chemicals. In fact, laboratory tests found the natural extracts to have little or no natural antimicrobial attributes of their own.3
So, even if commercial GSE products areeffective, they likely aren’t natural remedies at all.
More Sour Than Sweet…
The truth is, you’ll find GSE as an ingredient in plenty of products that aren’t all-natural anyway, such as cosmetics, skincare products, cleaning products, and more.
It is also available as a liquid that you can apply topically, as well as capsules that can be taken orally.
GSE appears to be safe and nontoxic, although you should avoid using it if you also take warfarin (Coumadin), since the synthetic preservatives in many GSE products may also thin the blood.
In addition, GSE decreases how the body breaks down estrogen and might increase estrogen levels. There’s some concern that GSE may also adversely interact with a number of drugs, including birth control pills, calcium channel blockers, psychiatric drugs, and statins, among others.
In my view, grapefruit seed extract’s reputation has gone a little sour, and it’s difficult to recommend it because of the dearth of good research behind the product.
Despite the promises you’ll hear online and in the media, I suggest taking a pass on GSE—unless adequate research ultimately bears out its supposed benefits.
And remember, keep an open mind to new ideas, but ALWAYS do your own homework…and combine that with common sense to figure out what’s best for YOU.
1Adeneye AA. Hypoglycemic and hypolipidemic effects of methanol seed extract of Citrus paradisi Macfad (Rutaceae) in alloxan-induced diabetic Wistar rats. Nig Q J Hosp Med. 2008 Oct-Dec;18(4):211-5.
2Adeneye AA. Methanol seed extract of Citrus paradisi Macfad lowers blood glucose, lipids and cardiovascular disease risk indices in normal Wistar rats. Nig Q J Hosp Med. 2008 Jan-Mar;18(1):16-20.
3Ganzera M, Aberham A, Stuppner H. Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract. J Agric Food Chem. 2006 May 31;54(11):3768-72.
4Bekiroglu S, Myrberg O, Ostman K, et al. Validation of a quantitative NMR method for suspected counterfeit products exemplified on determination of benzethonium chloride in grapefruit seed extracts. J Pharm Biomed Anal. 2008 Aug 5;47(4-5):958-61.
5Sugimoto N, Tada A, Kuroyanagi M, et al. [Survey of synthetic disinfectants in grapefruit seed extract and its compounded products]. Shokuhin Eiseigaku Zasshi. 2008 Feb;49(1):56-62.
6Avula B, Dentali S, Khan IA. Simultaneous identification and quantification by liquid chromatography of benzethonium chloride, methyl paraben and triclosan in commercial products labeled as grapefruit seed extract. Pharmazie. 2007 Aug;62(8):593-6.
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