Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Phenolic compounds may explain Mediterranean diet benefits

10.11.2005


Blood vessels appear healthier after people consume olive oil high in phenolic compounds



Phenolic compounds in olive oil, which have antioxidant, anti-inflammatory and anti-clotting properties, may explain cardiovascular health benefits associated with the so-called Mediterranean Diet, according to a new study in the Nov. 15, 2005, issue of the Journal of the American College of Cardiology.

"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," said Francisco Pérez Jiménez, M.D., Ph.D., from the Reina Sofia University Hospital in Córdoba, Spain.


The researchers, including lead author Juan Ruano, M.D., Ph.D., fed breakfasts including olive oil (that was either high or low in phenolic content) to 21 study participants (5 men, 16 women) who had high cholesterol levels, but were otherwise apparently healthy. The functioning of the endothelium (the inner lining) of small blood vessels of the fingers (instead of "in the arms") of participants and the concentrations of certain components in blood serum, including nitric oxide, improved after the polyphenol-rich breakfast.

"This is the first study that shows a direct benefit of an olive oil with high content in phenolic compounds on endothelial function in vivo," Dr. Pérez Jiménez said.

After fasting overnight, the participants reported to the hospital, where they ate a breakfast of 60 grams of white bread with 40 milliliters of virgin olive oil, a relatively high-fat meal. The meals also included vitamin A supplementation. Over the next four hours, blood samples were taken and the researchers used Doppler laser to measure endothelial responses to sudden changes in blood flow, which were produced by inflating and then deflating a blood pressure cuff. The response is known as ischemic reactive hyperemia. Poor responsiveness to this sort of blood flow test is considered an early warning sign of cardiovascular disease. Previous studies have linked high-fat meals to poor endothelial function lasting for several hours after eating.

In order to focus on the role of phenolic compounds, the researchers put each participant through the process twice in a randomized order, once using olive oil naturally high in phenolic compounds (400 parts per million) and once with the same brand of olive oil that had been processed to remove most of the phenolic compounds (80 parts per million remaining).

"We think, looking at our results, that the reduction in oxidative stress and the increase in the nitric oxide bioavailability are behind the observed improvement in ischemic reactive hyperemia," Dr. Pérez Jiménez said.

Dr. Pérez Jiménez said that olive oil may be superior to seed oils because it is a natural juice, pressed from the olives, so it does not go through the type of processing needed to extract oil from seeds, such as sunflowers, soybeans and rapeseeds. Nevertheless, he said further studies should be done to investigate whether phenolic compounds in olive oil can be linked to improved health outcomes.

"Although our study shows a direct benefit of an olive oil with high content in phenolic compounds on endothelial function in humans, carefully controlled studies in appropriate populations, or with a large sample size, are required to definitively establish the in vivo antioxidant properties of these components in relation to cardiovascular disease outcomes. On the other hand, some data suggest that endothelial dysfunction could be a surrogate end point for prediction of cardiovascular risk, but we need more information on the utility of the different methods to evaluate endothelial dysfunction," Dr. Pérez Jiménez said.

Robert F. Wilson, M.D., from the University of Minnesota in Minneapolis, who was not connected with this study, noted that health benefits of a Mediterranean diet were described over 50 years ago.

"This study demonstrates one possible mechanism by which olive oil rich in phenolic substances improves the functioning of the circulation. 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," Dr. Wilson said.

Dr. Wilson pointed out that not all olive oils have a high phenolic content.

"So these results might not be true for all olive oil on the shelf at the grocery store," he said.

Juan J. Badimon, Ph.D., F.A.C.C., from the Mount Sinai School of Medicine in New York, New York, who also was not connected with this study, said it was well-designed and will help address controversy about whether olive oil benefits or impairs blood vessel health.

"One of the beauties of this study is that using a randomized, sequential, crossover study, so that the same patients were exposed to the same oil, once with low phenolic content and the other with high phenolic content, the only variable in this study is the phenolic content of the olive oil," Dr. Badimon noted. "These results indicate that a very small change in diet, like using olive oil with a high phenolic content may have a significant impact in the progression of atherosclerosis."

Amy Murphy | EurekAlert!
Further information:
http://www.acc.org

More articles from Health and Medicine:

nachricht Tracking movement of immune cells identifies key first steps in inflammatory arthritis
23.01.2017 | Massachusetts General Hospital

nachricht Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>