Olive oil polyphenols’ heart benefits boosted: Human study

According to results from the EurOlive Study, a daily dose of olive oil polyphenols increased levels of oxidized LDL autoantibodies (OLAB), which reduced levels of oxidized LDL, an accepted risk factor for artery hardening (atherosclerosis).

The EurOlive study involves researchers from universities in five European countries and is examining the potential benefits of consuming polyphenol-rich olive oil at real-life olive oil doses.

“A direct protective role of OLAB on atherosclerosis generation has been previously established and our results provide further support to recommend the use of polyphenol-rich olive oil as a source of fat, particularly for individuals presenting a high oxidative status,”​ wrote the researchers in Clinical Nutrition​.

Olive oil phenolic compounds, such as oleuropein and cafeic acid have attracted attention because of their potential anti-diabetic, anti-atherosclerotic and anti-inflammatory properties. Such compounds have been also associated with the antioxidant activity of olive oil.

Study details​

The EurOlive researchers recruited 200 health men and randomly assigned then to three week intervention sequences to consume 25 milliliters per day of olive oils containing different levels of phenolic compounds. The high group’s dose was 366 mg per kg of olive oil, the medium dose was 164 mg/kg, and low dose was 2.7 mg/kg.

Results showed that OLAB levels were inversely associated with oxidized LDL levels and that consumption of the polyphenol-rich oil was associated with an increase in OLAB levels. Indeed, the increase in OLAB levels were dose-dependent, so the higher the polyphenol content, the greater the OLAB increase, said the researchers.

Take home​

“In our European populations we observed an inverse relationship between oxLDL concentrations and OLAB,”​ wrote the researchers.

“On the basis of our results two mechanisms could be implied in high OLAB levels linked to high olive oil phenolic compounds: 1) an immune response stimulation by olive oil phenolic compounds, and 2) a lack of clearance of free OLABS due to a reduction in oxLDL levels by olive oil phenolic compounds,”​ they concluded.

Source: Clinical Nutrition​
Published online ahead of print, doi: 10.1016/j.clnu.2011.01.013
“The effect of olive oil polyphenols on antibodies against oxidized LDL. A randomized clinical trial”​
Authors: O. Castaner, M. Fito, M.C. Lopez-Sabater, H.E. Poulsen, et al. for the EUROLIVE Study Group