Olive oil is a fundamental natural and healthy ingredient in the Mediterranean diet. Its protective effects against diseases associated with oxidative stress such as cardiovascular, neurodegenerative or cancer were attributed until now to its high content of monounsaturated fatty acids.
The EU-funded project EUROLIVE ("The effect of olive oil on oxidative damage in European populations") studied the possibility that other chemical factors also contribute to the documented health benefits of olive oil.
Its partners, led by a scientific team from the Hospital del Mar Institute for Medical Research (IMIM) in Barcelona (Spain), set out to find out whether olive oil rich in phenolic compounds (such as virgin olive oil) offered benefits for health other than those already known to offer other types of olive oil.
The team carried out six clinical trials in which two hundred healthy volunteers received twenty-five milliliters per day of three types of olive oil, each with a different polyphenol content, for three weeks. The dose is similar to the daily amount normally ingested in Mediterranean countries.
The results showed that the higher the polyphenol content, the higher the HDL level (also called good cholesterol).
In addition positive effects were registered regarding the atherogenic index (the total of cholesterol based on HDL cholesterol) and it was observed that the oxidative damage of the lipids presented a linear descent relation with the polyphenol content of the olive oil. The oxidation of lipids is a high risk factor for the development of ischemic heart disease.
Finally, the results of EUROLIVE showed that the consumption of twenty-five milliliters daily of olive oil, in substitution of other fats, did not cause an increase in weight in the participants.
For many, these results definitely tip the balance in favor of the antioxidant properties of polyphenols in olive oil and confirm the added value of virgin olive oil against other oils when it comes to protecting against heart disease and other risk factors .
EUROLIVE received 1.9 million euros of financing from the European Union. Those responsible finished their work in December 2004.
For more information, see:
Information sheet of the project http://cordis.europa.eu/projects/rcn/64505_es.html
Hospital del Mar Institute of Medical Research (IMIM) http://www.imim.es/infocorporativa/es_fundacio.html