Aug. 28, 2008 -- People have been using olive leaf medicinally for millennia.
The ancient Egyptians revered the leaves. Ancient Greeks used them to clean wounds, and the original Olympic athletes were crowned with a wreath of olive leaves. The olive leaf is even mentioned in the Bible for its purported healing properties.
So it's no wonder that scientists today are looking at ways to use olive leaf, specifically for one of modern society's biggest and sneakiest health problems -- high blood pressure.
An earlier study showed that when rats were given olive leaf extract, their blood pressure dropped.
Now researchers in Germany and Switzerland have looked at how sets of identical human twins with borderline hypertension responded to taking olive leaf extract. Identical twins were used to help keep the data consistent, because genetic differences can make people respond differently to the same treatments.
The extract was obtained from dry olive leaves and put into capsule form.
Two experiments were carried out. One compared twins who took 500 milligrams of olive leaf extract a day at breakfast with a comparison group of their siblings who didn't. A second compared a group who took 500 milligrams a day to those who took 1,000 milligrams a day. A total of 40 people participated, aged 18 to 60; 28 women and 12 men.
Here are the results:
Those who took the highest daily dosage of olive leaf extract (1,000 milligrams) received the highest benefits -- "significantly" lowering their cholesterol and blood pressure when compared to the group that took 500 milligrams.
At the end of the eight-week study, the group that took 1,000 milligrams per day had dropped their systolic blood pressure (the "top" number) by an average of 11 points.
The participants who received 500 milligrams of olive leaf extract dropped their systolic blood pressure by five points, and those who took no supplements saw their blood pressure edge up by two points. Neither one of these changes was felt to be statistically significant.
Researchers, led by lead author Tania Perrinjaquet-Moccetti of Frutarom (a Swiss manufacturer of the olive leaf extract), note that they were not looking for what dosage might be most effective, but rather whether there was a blood pressure lowering effect at all.
The authors also note a "significant" reduction in LDL ("bad") cholesterol in those twins who took the olive leaf extract, but the specific data regarding these results was not presented in the paper.
The authors call for more investigation into the possible benefits of olive leaf extract on both blood pressure and cholesterol levels.
Results are published in the September issue of Phytotherapy Research. The research was funded by Frutarom.