Olive Leaf Tea: Tradition, Evidence and Safety
Olive leaves have been brewed as a bitter folk tea for generations, from southern Europe and North Africa to Latin America. Here is what European regulators accept, what the blood pressure studies really show, and how to make a gentle cup.
Most of us know the olive tree for its fruit and oil. Its narrow, silvery leaves have a quieter history. They have been dried and brewed as a folk remedy in many places, including Spain, Greece, Italy, Bulgaria, Morocco, Tunisia, the Canary Islands, Madeira and parts of Latin America.
The tea is pale, slightly grassy and noticeably bitter. It is now sold widely as a health tea, often with big promises. The real picture is more modest, and there are a few people who should not drink it at all.
How olive leaf has been used
In its review of olive leaf, the European Medicines Agency (EMA) describes a long folk tradition of using the leaves for high blood pressure, diabetes, to increase urine, for fevers and for digestive complaints. The leaves contain a compound called oleuropein, which researchers have studied closely.
Of all these uses, European experts accepted only one for self-care products: as a traditional herbal medicine to help the kidneys pass water in mild cases of water retention, after a doctor has ruled out serious causes. This is based on long use, not on clinical trials. The EMA did not accept the blood pressure use for self-medication.
Gentle Olive Leaf Tea
You need
- water, just off the boil250 ml (1 cup)
- dried olive leaves, crumbled1 tsp (about 1 to 2 g)
- thin slice of lemon or a small sprig of mint, optional1
Method
- Put the crumbled olive leaves in a cup or small teapot.
- Pour over the hot water, cover and steep for 5 to 10 minutes. Longer steeping makes it more bitter.
- Strain, add the lemon or mint if you like, and let it cool to a comfortable sipping temperature.
Tips
- Use leaves sold for tea, or dry leaves only from trees you know have not been sprayed.
- This is a lighter cup than the medicinal amounts in the EMA monograph, which uses several grams of leaf per dose, several times a day.
- If you find it too bitter, mix the leaves half and half with a milder herb such as mint or lemon verbena.
What the evidence says
Blood pressure is the most studied claim, but the studies are few and mostly of olive leaf extract, not tea. The strongest one described by the EMA compared an olive leaf extract with captopril, a blood pressure drug, in people with mild high blood pressure. Blood pressure fell by a similar amount in both groups, but many participants dropped out, which weakens the result. Other studies were small or had no proper control group.
For blood sugar, most of the evidence comes from animal studies. The EMA also notes that human data on how the body handles olive leaf are limited, and that safety studies on genetic damage, cancer, pregnancy and development are missing.
In short, olive leaf tea is a traditional drink with interesting early research, not a treatment. If you have high blood pressure or diabetes, it should never replace your prescribed medicine.
Why it matters if you take medicines
Because people drink olive leaf for blood pressure, blood sugar and water retention, it can add to the effect of medicines for the same problems. Lab work described by the EMA shows that oleuropein can block some liver enzymes that break down drugs. No real-life interactions have been reported, but they have not been well studied either.
If you take medicine for blood pressure, diabetes, water tablets (diuretics) or lithium, talk to your doctor or pharmacist before drinking olive leaf tea regularly.
Questions people ask
Does olive leaf tea lower blood pressure?
A few small studies of olive leaf extract suggest it might, but the evidence is weak, and European regulators did not accept this use for self-care. It is not a replacement for blood pressure medicine.
Is olive leaf tea the same as olive oil?
No. The tea is made from the leaves, while olive oil comes from the fruit. They contain different amounts of different compounds, so research on olive oil does not apply to the tea.
How long can I drink it for?
The EMA describes traditional use for 2 to 4 weeks, and advises seeing a doctor if symptoms last more than a week. For longer use, check with your doctor.
Sources
- Oleae folium (olive leaf): herbal medicinal product — European Medicines Agency
- Assessment report on Olea europaea L., folium — European Medicines Agency
This article is for general information only and is not medical advice. Herbs can interact with medicines and health conditions. Talk to a doctor or pharmacist before trying a herbal remedy, especially if you are pregnant, breastfeeding, giving it to a child, or taking any medication.
