Olive Leaf and Olive Leaf Tea

The olive tree gives more than fruit. The leaves that come off with every pruning have been put to use around the Mediterranean for centuries — as animal fodder, in traditional practice, and more recently as tea and extract.

What is in the leaf?

The prominent compound in olive leaf is oleuropein. It is the same substance that makes raw fruit bitter, and it is more concentrated in the leaf than in the fruit. Alongside it are hydroxytyrosol, tyrosol, verbascoside and flavonoids.

These belong to the polyphenol group and show antioxidant activity in the laboratory. Most of the claims built on that foundation, however, are not authorised — we return to this below.

Gathering and drying the leaves

• Leaves are collected during pruning, preferably in spring.
• They must come from an unsprayed tree; unlike fruit, leaves are not washed and peeled.
• Rinse in cold water to remove dust, then drain.
• Dry them spread thinly in shade, somewhere airy. Direct sun breaks down the polyphenols.
• They are dry when they crackle as you crumble them. Store in a glass jar away from light.

Brewing the tea

Steeping gives a better result than boiling; a long boil brings out bitterness and tannin.

1. One teaspoon of dried, crumbled leaf per cup (200 ml) of water is enough.

2. Boil the water, take it off the heat and wait a minute (around 90 °C).

3. Pour over the leaves, cover, and steep for 7-10 minutes.

4. Strain. A slice of lemon suits it; a little honey rounds it off better than sugar.

The taste is faintly bitter and herbal. Steeped longer, the bitterness becomes pronounced.

Limits — without overstating

Honesty is required here. Olive leaf tea is credited online with a long list of effects: lowering blood pressure, strengthening immunity, helping with infections. None of these is an authorised health claim under European Food Safety Authority rules.

The only authorised claim concerning the olive relates to olive oil polyphenols contributing to the protection of blood lipids from oxidative stress, and it depends on a specific quantity of hydroxytyrosol — detailed in oleocanthal and polyphenols.

Points to keep in mind:

• If you take blood pressure medication, consult your doctor; herbal products can alter drug effects.
• The same applies to blood sugar medication.
• During pregnancy and breastfeeding, herbal teas should not be taken regularly without medical approval.
• A cup or two a day is a sensible limit; more is not better.

The information on this page is general information and not medical advice.

Other uses of the leaf

• Fodder. Leaves left from pruning are traditionally fed to sheep and goats around the Mediterranean.
• Extract. Sold as a supplement with standardised oleuropein content; supplement use should involve your doctor.
• Compost. Leaves and thin prunings are a source of organic matter in the garden.

What comes from each part of the tree is gathered together in products of the olive.