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 New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute

nachricht Distrust of power influences choice of medical procedures
01.08.2018 | Johannes Gutenberg-Universität Mainz

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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>