Olive Oil Reduces Atherosclerosis

BARCELONA, Spain—Olive oil polyphenols promote the growth of antibodies that help reduce oxidative low-density lipoprotein (LDL), which could help reduce hardening of the arteries, according to a recently published study from the EUROLIVE Study Group (Clin Nutr. 2011 Mar 2. DOI:10.1016/j.clnu.2011.01.013). What’s more, the researchers found olive oil polyphenols encourage the antibodies to grow even more in subjects who experience higher lipid oxidative damage.

Researchers, who span Europe from Spain, Denmark and Finland to Germany and Italy, assigned 200 healthy men to three-week sequences of 25 mL/day of three olive oils with high (366 mg/kg), medium (164 mg/kg) and low (2.7 mg/kg) phenolic content in a crossover, controlled trial. They studied the plasma concentration of oxidized LDL auto antibodies (OLAB), which have shown in previous studies to protect against atherosclerosis.

Olive oil phenolic content increased OLAB generation, with the effect being stronger at higher concentrations of oxidized LDL (P=0.020 for interaction). A direct relationship was observed between OLAB and the total olive oil phenol content in LDL (R=0.209; P=0.014). OLAB concentrations, adjusted for oxidized LDL, increased directly in a dose-dependent manner with the polyphenol content of the olive oil administered (P=0.023). Plasma OLAB concentration was inversely associated with oxidized LDL (P<0.001).

This study was the latest from the EUROLIVE consortium, which focuses on the study of the health benefits of virgin and common olive oil in prevention of pathologies that affect cardiovascular function and their cost/benefit ratio. The group conducts studies in humans designed to obtain scientific evidence on the impact of olive oil, and its phenolic compounds, on oxidative stress and damage in several European populations. In all studies, the three types of olive oils (low, medium and high phenolic content) are administered to healthy volunteers.

Previous studies from the group have reported not only the monounsaturated fatty acid content of olive oil is responsible for the protective effects of the oil on health; the polyphenols present in olive oil, and mainly in virgin olive oil, also have a protective role on cardiovascular risk. Specifically, a 2007-published study found the polyphenol content of an olive oil can account for further benefits on high-density lipoprotein (HDL) cholesterol and oxidative damage than those provided by the monounsaturated fatty acid content of the olive oil (Ann Intern Med. 2007 Mar 6;146(5):394).