Particularly note the last paragraph:
"The authors found that after test subjects took olive oil spiked with
phenolic compounds, their blood vessels could dilate better, which could
improve blood flow. These findings are particularly interesting because
similar studies after high-fat meals, like a burger and fries, showed
impairment of normal blood vessel functions."

Original page:
http://www.webmd.com/content/Article/115/111589.htm

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Olive Oil's Heart-Healthy Secret

Phenolic Compounds in Olive Oil May Explain Mediterranean Diet's Benefits

     By Jennifer Warner
     WebMD Medical News  Reviewed By Louise Chang, MD
     on Friday, November 11, 2005

Nov. 11, 2005 - An ingredient found in olive oil may be largely responsible
for the heart-healthy benefits attributed to the Mediterranean diet,
according to a new study.

Researchers tested the effects of eating a meal of olive oil and bread and
found people's blood vessels appeared healthier after eating olive oil rich
in phenolic compounds.

Phenolics are plant-based compounds that are believed to have antioxidant,
anti-inflammatory, and anticlotting properties and are found in higher
concentrations in less processed oils.

Researchers say their results suggest virgin olive oil may be better for the
heart than seed oils because it is a natural juice that does not go through
the processing needed to extract oil from seeds, such as sunflowers and
soybeans. Therefore, the oil retains more of its original nutrients.

"It could be that the beneficial effect of the Mediterranean diet on
cardiovascular disease and arteriosclerosis depends on the synergistic
effects of the different nutrients that constitute complete foods and, as an
example, virgin olive oil is more than fat because it is a real juice with
other healthy micronutrients," says researcher Francisco Pérez Jiménez, MD,
PhD, from the Reina Sofia University Hospital in Córdoba, Spain, in a news
release.

Phenolics Behind Olive Oil's Benefits

In the study, which appears in the Journal of the American College of
Cardiology, researchers compared the effects on blood vessel function of
eating virgin olive oil high in phenolics and olive oil that had been
stripped of most of its phenolics.

On different days, 21 otherwise healthy adults with high cholesterol ate a
breakfast of white bread and 40 milliliters (a little more than 2.5
tablespoons) of each of the olive oils. During the next four hours,
researchers took blood samples and monitored the participants' blood flow.

The results showed that the functioning of the inner lining of the small
blood vessels of the fingers of the participants and the concentration of
certain healthy components in the blood, such as nitric oxide, improved
after the breakfast of high-phenolic olive oil. But no such changes were
found after the low-phenolic meal.

Although more studies are needed to confirm these results, experts say the
findings suggest that even a very small change in diet, like using olive oil
rich in phenolic compounds, may have a significant effect in reducing the
risk of atherosclerosis (hardening of the arteries) and heart disease.

"This study demonstrates one possible mechanism by which olive oil rich in
phenolic substances improves the functioning of the circulation," says
Robert F. Wilson, MD, of the University of Minnesota in Minneapolis, in a
news release. "The authors found that after test subjects took olive oil
spiked with phenolic compounds, their blood vessels could dilate better,
which could improve blood flow. These findings are particularly interesting
because similar studies after high-fat meals, like a burger and fries,
showed impairment of normal blood vessel functions."

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SOURCES: Ruano, J. Journal of the American College of Cardiology, Nov. 15,
2005; vol 46: pp 1864-1868. News release, American College of Cardiology.

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