Written by Greg Arnold, DC, CSCS. In a study of 36 non-smoking men between 20 and 60 years of age there was a 22% decrease in oxidized LDL cholesterol in the virgin olive oil group compared to a 9% decrease in the refined olive oil group.
Olive oil’s role in helping health has been attributed to its high levels of antioxidants called polyphenols (1). Now a new study (2) has found that olive oil’s heart health benefits extend to helping keep LDL cholesterol healthy. In the study, 36 non-smoking men between 20 and 60 years of age and participating in the EUROLIVE study (3) were given 25 milliliters (22 grams) of either virgin olive oil (containing 629 mg/L of polyphenols per serving) or refined olive oil (0 mg/L polyphenols ) each day for three weeks, with the olive oil consumed across three meals throughout the day. The researchers obtained blood samples from the patients before and after the study to measure for damage to LDL cholesterol (“oxidized LDL”) since it is now regarded as a marker for the development of atherosclerosis and cardiovascular heart disease (4).
By the end of the study, those in the virgin olive oil group had an increase in two types of polyphenols, with a 50% increase in hydroxytyrosol sulfate (2.4 to 3.6 nanograms/milligram) and a 28% increase in homovanillic acid sulfate (13.3 to 17.0 nanograms/milligram). In the refined olive oil group, there was a 4% increase homovanillic acid (13.9 to 14.4 ng/mg) and a 13% increase in hydroxytyrosol sulfate. As a result, oxidation of LDL cholesterol in the virgin olive oil group was 2.5 times less, compared to the refined olive oil group. Specifically, there was a 22% decrease in oxidized LDL cholesterol in the virgin olive oil group (50 to 39 Units/Liter) compared to a 9% decrease in the refined olive oil group (46 to 42 Units/Liter).
For the researchers, “the phenol concentration of olive oil [decreases LDL oxidation] after sustained, daily consumption” and that this study “supports the…antioxidant role of olive oil phenolics compounds.”
Source: de la Torre-Carbot, Karina, et al. “Elevated circulating LDL phenol levels in men who consumed virgin rather than refined olive oil are associated with less oxidation of plasma LDL.” The Journal of nutrition 140.3 (2010): 501-508.
© 2010 American Society for Nutrition.
Posted April 9, 2010.
References:
- Maria-Isabel C. The Effect of Polyphenols in Olive Oil on Heart Disease Risk Factors: A Randomized Trial. Ann Int Med 2006; 145(5): 333-341.
- de la Torre-Carbot K. Elevated Circulating LDL Phenol Levels in Men Who Consumed Virgin Rather Than Refined Olive Oil Are Associated with Less Oxidation of Plasma LDL. Jou Nutr 2010; 140 (3): 501-508.
- Covas MI, Nyyssonen K, Poulsen HE, Kaikkonen J, Zunft HJ, Kiesewetter H, Gaddi A, de la Torre R, Mursu J, et al. The effect of polyphenols in olive oil on heart disease risk factors: a randomized trial. Ann Intern Med. 2006;145:333–41.
- Meisinger C, Baumert J, Khuseyinova N, Loewel H, Koenig W. Plasma oxidized low-density lipoprotein, a strong predictor for acute coronary heart disease events in apparently healthy, middle-aged men from the general population. Circulation. 2005;112:651–7
