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Myth buster: Does olive leaf extract work?

Olive branch with leaves and olives

Olive leaf extract is touted as a cure-all for everything from colds to chronic fatigue and diabetes. But can you trust the claims?

On a recent trip to Greece and Turkey, I was struck by the sheer age and size of the olive trees, which were thriving in a dry climate on a rocky hillside in little soil. A tree so hardy and able to resist attacks from pests must contain substances that warrant study, I thought.

The olive leaf has been used medicinally for thousands of years. These days it’s favoured by alternative practitioners as a ‘natural antibiotic’ to kill bacteria and fungi, and stimulate the immune system. It’s thought to assist with persistent conditions, such as chronic fatigue.

There’s also clinical evidence of a blood-pressure-lowering effect and preliminary studies have shown a blood-glucose-lowering effect, suggesting it may be used in future diabetes treatments. Anti-arthritis, anti-aging, cancer prevention and anti-inflammatory claims have also been made, but research has so far been inconclusive.

How does olive leaf extract ‘work’?

At present, scientists believe that the active compound in olive leaves is oleuropein, a natural polyphenol – a type of antioxidant that is also found in extra-virgin olive oil (but is more concentrated in olive leaf extract). Oleuropein deters insects from attacking the trees and, in the lab, kills bacteria and moulds.

Olive leaf extract is also comprised of phytonutrients, such as flavonoids, plus a number of catechins, which all have an impressive antioxidant capacity; much higher than vitamin C and even more than green tea extract.

Lastly, olive leaf extract contains essential nutrients, such as iron, zinc, selenium, chromium, vitamin C, beta-carotene and a wide range of amino acids.

What’s olive leaf extract good for?

Degree-qualified naturopath, herbalist and nutritionist Bridget Carmady prescribes olive leaf extract as a daily immune herb (much like vitamin C) for people who are prone to picking up colds and flus, such as parents of young children, and for anyone with symptoms of heart disease (high blood pressure or high cholesterol). It can also be used as a sore throat gargle, treatment for fungal infections, such as tinea or vaginal Candida, and for viral infections such as herpes.

As with all herbal remedies, source a quality brand and ask for advice from a qualified herbalist so you know you’re getting the right product in the right dosage.

The bottom line

Lab tests are promising, and if it’s helping with your symptoms, great! Its long-term safety has not been thoroughly tested, however, so be cautious about taking this if you’re pregnant or ill.

Article sources and references

Date modified: 27 April 2021
First published: Oct 2010


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