A supplement containing olive leaf extract may help lower
pressure and cholesterol in people on the brink of developing
high blood pressure, a new study suggests.
The leaves of the olive tree have been used for medicinal
purposes since ancient times, and modern lab research suggests
that olive leaf extracts have antibacterial, anti-inflammatory
and antioxidant actions. There is also evidence that the extracts
have properties that could lower blood pressure.
The current study, published in the journal Phytotherapy
Research, included 20 sets of identical twins with "borderline"
hypertension -- blood pressure that is above the optimal level
of 120/80, but below the cutoff of 140/90 used to diagnose
high blood pressure.
One member of each twin pair was given tablets containing
olive leaf extract, while the other received no supplements
but did get lifestyle advice on lowering blood pressure --
the standard approach to managing borderline hypertension.
Half of the supplement users took 500 mg of olive leaf extract
per day, and the other half took 1,000 mg.
After eight weeks, the study found, supplement users on the
higher dose showed a substantial dip in their blood pressure
overall -- from an average of 137/80 to 126/76. They also
saw their average level of "bad" LDL cholesterol fall.
In contrast, the twins who received no supplements showed
no significant change in their blood pressure and a smaller
improvement in cholesterol, according to the researchers,
led by Tania Perrinjaquet-Moccetti, a molecular biologist
with Frutarom Switzerland Ltd. in Wadenswil.
The company makes the olive leaf extract used in the study,
a product called Benolea.
The benefits seen in this study can be attributed to the
various "bioactive components" of the olive leaf, Perrinjaquet-Moccetti
told Reuters Health. The most significant of these, she noted,
is a compound called oleuropein.
Research shows that oleuropein acts as an antioxidant and
can help relax and dilate the blood vessels.
However, Perrinjaquet-Moccetti added, no single ingredient
of the olive leaf extract accounts for its blood pressure
Olive leaf extracts are available over the counter, but people
with high blood pressure, or any medical condition, are generally
advised to consult their doctor before self-prescribing a
Perrinjaquet-Moccetti said it "would be wise" for patients
to mention any supplement use to their doctor, especially
if they are taking any medications. Herbal supplements have
the potential to interact with drugs, which could interfere
with the medication's effectiveness or create side effects.
SOURCE: Phytotherapy Research, September 2008.