Navigation Links
Phenolic compounds may explain Mediterranean diet benefits

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 responsiv eness 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 bene fits 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."


Source:American College of Cardiology

Related biology news :

1. Researchers discover chemical compounds that affect plant growth
2. Bacterial genome sheds light on synthesizing cancer-fighting compounds
3. Scientists discover the bodys marijuana-like compounds are crucial for stress-induced pain relief
4. Evolution of taste receptor may have shaped human sensitivity to toxic compounds
5. Novel compounds show promise as safer, more potent insecticides
6. Metal-containing compounds show promise as HIV weapon
7. Seaweed yields new compounds with pharmaceutical potential
8. Marijuana-like compounds suppress the immune response
9. Legume compounds may help cancer treatment
10. Microbes transform safest PBDEs into more harmful compounds
11. Harvard scientists identify compounds that stimulate stem cell growth in the brain
Post Your Comments:

(Date:11/17/2015)... November 17, 2015 Paris ... 2015.  --> Paris , qui ... DERMALOG, le leader de l,innovation biométrique, a inventé ... passeports et empreintes sur la même surface de balayage. ... et l,autre pour les empreintes digitales. Désormais, un seul ...
(Date:11/12/2015)...  A golden retriever that stayed healthy despite having ... provided a new lead for treating this muscle-wasting disorder, ... of MIT and Harvard and the University of São ... Cell, pinpoints a protective gene that boosts ... The Boston Children,s lab of Lou Kunkel , ...
(Date:11/10/2015)... 10, 2015  In this report, the ... of product, type, application, disease indication, and ... report are consumables, services, software. The type ... biomarkers, efficacy biomarkers, and validation biomarkers. The ... diagnostics development, drug discovery and development, personalized ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... Md. , Nov. 25, 2015  PharmAthene, Inc. ... Directors has adopted a stockholder rights plan (Rights Plan) ... net operating loss carryforwards (NOLs) under Section 382 of ... --> PharmAthene,s use of its NOLs ... "ownership change" as defined in Section 382 of the ...
(Date:11/25/2015)... Nov. 25, 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ: ... business and prospects remain fundamentally strong and highlights ... doxorubicin) recently received DSMB recommendation to continue the ... review of the final interim efficacy and safety ... Endpoint in men with heavily pretreated castration- and ...
(Date:11/24/2015)... KUALA LUMPUR, Malaysia , Nov. 24, 2015 ... the global contract research organisation (CRO) market. The ... to result in lower margins but higher volume ... With increased capacity and scale, however, margins in ... Contract Research Organisation (CRO) Market ( ...
(Date:11/24/2015)... Worcester, Mass. (PRWEB) , ... November 24, 2015 ... ... need to maintain healthy metabolism. But unless it is bound to proteins, copper ... Institutes of Health (NIH), researchers at Worcester Polytechnic Institute (WPI) will conduct a ...
Breaking Biology Technology: