Mountain Tea Research: What Science Really Shows

Few herbs have as glowing a reputation as Greek mountain tea. Search for it and you will read that it fights colds, protects the brain, prevents memory loss, calms anxiety and is packed with antioxidants.

Some of these ideas have a little research behind them. Most come from lab dishes and animal studies, and none of them proves a cure. Here is a plain guide to what is known, sorted by how strong the evidence is.

What Europe's herbal review found

The most careful look at mountain tea comes from the European Medicines Agency (EMA). Its committee on herbal medicines assessed four Sideritis species and recognized them as a traditional herbal medicine for two uses in adults: relief of cough associated with a cold, and relief of mild stomach and gut discomfort.

Traditional means the decision rests on long-standing use, at least 30 years, including 15 in the European Union. It is not the same as proof from clinical trials. In fact, the EMA report states that there is a lack of clinical research and that controlled trials are needed. The main human data at the time came from a small study in 10 volunteers on how the body absorbs and excretes the plant's polyphenols.

EMA reviewed the topic again in 2023. It found no new data that would change its conclusions, so the traditional status stands.

What the evidence says

Lab and animal studies: In test tubes, Sideritis extracts have shown antimicrobial, antioxidant and anti-inflammatory activity. In rats, extracts reduced stomach damage and swelling, and one extract relaxed gut muscle in the lab. In aged mice, Sideritis extracts improved performance on memory tasks. A lab study of anti-inflammatory compounds suggested they might be worth studying for Alzheimer's disease, after further adequate research. None of this shows that a cup of tea does the same in people.

Human studies: The main trial gave 155 healthy adults aged 50 to 70 capsules of a concentrated Sideritis scardica extract or a placebo for 28 days. At the higher dose of 950 mg, people made fewer errors on one attention task and reported lower anxiety than with placebo. There was no effect on blood pressure or on other mood scales, and the lower dose had little effect. The study was sponsored by a company that employed some of the authors, and the researchers call for longer studies.

Bottom line: mountain tea may ease a cough with a cold or mild stomach discomfort, based on tradition. There is no proof that it cures or prevents colds, infections, memory loss, Alzheimer's disease, anxiety or any other disease.

Myth and fact, side by side

Myth: mountain tea boosts your immune system and stops colds. Fact: EMA's recognition covers relieving a cough that comes with a cold, based on tradition. No study shows it prevents colds.

Myth: it protects against Alzheimer's disease. Fact: the hints come from lab dishes and mice. No human study has tested this.

Myth: lots of antioxidants means it must be good for you. Fact: a review of Sideritis raeseri notes that Balkan species are rich in flavonoids with antioxidant activity in lab tests, but that does not show what happens in the body.

Myth: natural means it is safe in any amount. Fact: EMA's safety data are reassuring for adults, with no side effects reported and no toxicity in animal tests, but animal studies on reproduction and long-term effects are missing, so EMA keeps limits on who should use it and how much.

Questions people ask

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.