Turn to the Dark Side

Is your olive oil in an opaque bottle? If not, it may be quickly losing some of its ability to protect your blood vessels.

According to a recent study, antioxidants in virgin olive oil help relax blood vessels and improve circulation, which may lower people's risk of atherosclerosis and cardiovascular disease. However, the antioxidant value of olive oil can degrade after only a few months of exposure to heat and light. Store your olive oil in an opaque cruet and in a cool place.

In a small study, participants who suffered from high cholesterol were fed two high-fat meals. One meal included a virgin olive oil high in phenols, which have antioxidant properties. The other meal used olive oil that was low in phenols. Researchers measured blood flow at 2 hours and 4 hours following each meal and discovered that the phenol-rich virgin olive oil helped blood vessels to dilate, thereby improving circulation. Researchers believe phenols in olive oil improve blood vessel function by combating oxidative damage and increasing production of nitric oxide, a molecule that relaxes blood vessels. Exposure to air, light, and heat oxidizes olive oil, so maximize the nutritive value of your oil by storing it properly in a tightly-sealed, opaque container. As part of a heart-healthy lifestyle, use virgin olive oil in flavorful vinaigrettes or any of your favorite recipes that require oil. Virgin olive oil tends to be higher in phenolic compounds than regular olive oil.

Phenolic content of virgin olive oil improves ischemic reactive hyperemia in hypercholesterolemic patients. Ruano, J., Lopez-Miranda, J., Fuentes, F., Moreno, J. A., Bellido, C., Perez-Martinez, P., Lozano, A., Gomez, P., Jimenez, Y., Perez Jimenez, F., Journal of the American College of Cardiology 2005 Nov 15;46(10):1864-1868. Epub 2005 Oct 24.

Virgin olive oil storage and stability. Giovacchino, L., Mucciarella, M.R., Costantini, N., Ferrante, M.L., Surricchio, G. and Sestili, S. 2002. Acta Horticulturae (ISHS) 586:567-569.