The science on olive leaf extract

Olive leaf extract is one of my favorite supplements on earth because it delivers more than one benefit according to several studies. It can be taken in tincture and capsule form, but when shopping for olive leaf, always look for “standardized” on the label, as it means it’s been tested and guaranteed to have that much of the active ingredient (oleuropein) in each capsule or serving.

Olive leaf has been shown in studies to kill bacteria on contact and thus many use it as a preventative immune system booster to ward of colds and other bugs. Some have described it as an “all-natural antibiotic.

Olive leaf 0.6% (w/v) water extract killed almost all bacteria tested, within 3 h. Dermatophytes were inhibited by 1.25% (w/v) plant extract following a 3-day exposure whereas Candida albicans was killed following a 24 h incubation in the presence of 15% (w/v) plant extract. Olive leaf extract fractions, obtained by dialysis, that showed antimicrobial activity consisted of particles smaller than 1000 molecular rate cutoffs. Scanning electron microscopic observations of C. albicans, exposed to 40% (w/v) olive leaf extract, showed invaginated and amorphous cells. Escherichia coli cells, subjected to a similar treatment but exposed to only 0.6% (w/v) olive leaf extract showed complete destruction. These findings suggest an antimicrobial potential for olive leaves. – April 2003 study in Mycoses.

More exciting however, is that olive leaf’s active ingredient, oleuropein, has been shown in many studies to have anti-cancer potential as well as positive impacts on the heart.

As always, talk with you doctor before taking any of my advice and know that olive leaf is not for anyone with kidney issues.

Sources: Markin D, Duek L, Berdicevsky I. In vitro antimicrobial activity of olive leaves. Mycoses. 2003;46(3-4):132-136. doi:10.1046/j.1439-0507.2003.00859.; Omar SH. Oleuropein in olive and its pharmacological effects. Sci Pharm. 2010;78(2):133-154. doi:10.3797/scipharm.0912-18; Menendez JA, Vazquez-Martin A, Colomer R, Brunet J, Carrasco-Pancorbo A, Garcia-Villalba R, Fernandez-Gutierrez A, Segura-Carretero A. Olive oil’s bitter principle reverses acquired autoresistance to trastuzumab (Herceptin™) in HER2-overexpressing breast cancer cells. BMC Cancer. 2007;7:80. doi:10.1186/1471-2407-7-80. De la Puerta R, Guttierrez VR, Hoult JRS. Inhibition of leukocyte 5-lipoxygenase by phenolics from virgin olive oil. Biochem Pharmacol. 1999;57:445–449.



1 thought on “The science on olive leaf extract”

  1. You know… I’ve tried to use Olive Leaf dried herb capsules in the past and I didn’t notice any difference. I wonder if it was because of my blood type and maybe there was a different herb that would work better for me than this. Though, I have a good friend who swears by this… but he is a different blood type! I see that you said to make sure it’s standardized (which it def. may not have been)… so I guess I will give it another shot. Always looking to expand the products I have for anti-bacterials.

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