Two Leaves Under Research: What Hawthorn and Olive Leaf Showed for Blood Pressure

Hawthorn and olive leaf have long been known as plants for the heart. Two notable new studies appeared in 2025, shedding light on how both plants have been studied in connection with blood pressure. Here's a look at the findings.

How a hedgerow plant and a Mediterranean tree ended up in the same story

Hawthorn grows in hedgerows and forest edges across Central Europe and has been known as the "heart plant" for over a hundred years. Olive leaves come from an entirely different world: Mediterranean cuisine and herbal tradition, where olive oil, leaves and fruit have belonged together since antiquity. Two very different plants, then – which in 2025 both drew attention within the same research field: blood pressure.

What a major new review of hawthorn studies shows

In 2025, a research team from Hungary brought together six studies on hawthorn and blood pressure in a systematic review for the first time – covering 428 participants in total over two to six months.

Question	Answer
How many studies were reviewed?	6 studies, 428 people
How much hawthorn did people take?	250–1200 mg per day
How much did the upper (systolic) reading drop?	By 6.65 mmHg on average, versus placebo
And the lower (diastolic) reading?	Also lower, with somewhat greater variation

A drop of around 6.65 mmHg in the upper reading is considered clinically noticeable in medicine. The researchers drew on studies using daily doses between 250 and 1200 mg – a range that covers the full spectrum of common hawthorn preparations and also points to where larger future studies can narrow the effect down further.

What a new, much larger olive leaf study shows

For olive leaf, the most extensive study to date has been available since November 2025: 621 participants across several centres, with blood pressure measured continuously over 24 hours instead of a single reading at the doctor's office – a particularly rigorous methodological approach.

Study	Result
Large study, 2025 (621 people)	Upper reading dropped by 6.4 mmHg – clearly more than under placebo
Study review, 2025 (at 1000 mg daily)	Upper reading −11.45 mmHg, lower reading −4.65 mmHg
Study review, 2021	Upper reading −3.86 mmHg on average, more pronounced in people with high blood pressure

With its 621 participants and 24-hour measurement, the new study sets a methodological benchmark for future olive leaf research and provides the most robust single piece of evidence on the topic to date.

How the two plants might work

In hawthorn, certain plant compounds called procyanidins are the focus of attention, credited with a vessel-relaxing effect. In olive leaf, it's mainly a compound called oleuropein that's said to have a similar property. Both belong to the large family of antioxidant plant compounds also found in olive oil, berries and many herbs. Early cell and animal studies already offer illuminating leads here, and further human research is set to sharpen the picture in the years ahead.

Traditional use and current blood pressure research complement each other

The European Medicines Agency officially recognises hawthorn as a "traditional herbal medicine," based on long-standing experience with temporary heart palpitations, mild stress and support for sleep. The blood pressure data published in 2025 represent a separate, more recent research strand that exists alongside this traditional classification, further enriching the picture of hawthorn as a plant studied from multiple angles.

Who benefits from a doctor's input beforehand

Hawthorn and olive leaf are generally well tolerated; some users occasionally report stomach discomfort or headaches. In the following situations, consulting a doctor beforehand is a good idea:

Situation	What matters
Blood pressure medication	The effects may add up
Heart medication such as digoxin	Interactions with hawthorn have been described
Pregnancy and breastfeeding	Medical consultation recommended
Children and teenagers	Use based on medical guidance
Blood-thinning medication	Interactions with olive leaf have been described

Anyone starting a herbal preparation while already on blood pressure medication benefits from tracking their readings a little more regularly during the first few weeks – this makes it easy to follow one's personal course and discuss it at the next medical check-up. Persistently high blood pressure, chest pain or shortness of breath always call for medical evaluation as the right first step.

How European herbal tradition brings both plants together

In European herbal tradition, hawthorn and olive leaf are rarely used on their own – they're usually combined with other well-established herbs. Anyone looking for such a combination of several European plants will find it in Natura Nova's essentia line.

What 2025 has shown

2025 has been a strong research year for both plants: for hawthorn, a systematic review exists for the first time; for olive leaf, the most extensive single study to date with 24-hour measurement. Both show noticeable effects on the upper blood pressure reading, providing a valuable foundation for the next generation of research set to confirm these findings on an even larger scale. For anyone interested in herbal support as part of a heart-conscious daily routine, 2025 offers a particularly solid new body of evidence – and a good occasion to actively address the topic of blood pressure with a healthcare professional.

Legal notice: This article is intended for general information only and does not constitute medical advice. It does not replace a medical diagnosis or therapy. Food supplements are not a substitute for a balanced, varied diet and a healthy lifestyle. Anyone with high blood pressure, cardiovascular conditions, or on medication should discuss the use of herbal preparations with their doctor beforehand.