A little extra olive oil might be good for your blood vessels. In a new US-Italian study, people with atherosclerosis showed significant improvement in inflammation and endothelial (the cells lining the blood vessels) function when given about two tablespoons daily of olive oil. Researchers at the Mayo Clinic and the Dipartimento di Scienze Farmaceutiche in Florence said this was the first such finding of its kind.
Why might olive oil combat inflammation and improve blood-vessel function? “In addition to its heart-healthy monounsaturated fatty acid content,” explains Jeffrey Blumberg, PhD, director of Tufts HNRCA Antioxidants Research Laboratory, “olive oil, especially the minimally processed extra virgin oil, contains more than 30 different phenolic compounds, a group of phytochemicals that include many with beneficial anti-inflammatory and vasodilating (enlarging blood vessels, which decreases blood pressure) actions.”
FIGHTING INFLAMMATION. The four-month study was completed by 52 participants at low to intermediate cardiovascular risk, all already suffering from endothelial dysfunction. They were randomly assigned to 30 milliliters daily of olive oil with or without added EGCG, an antioxidant found in tea, or to a control group.
Both olive-oil groups showed significantly improved endothelial function along with significant reductions in markers of inflammation; researchers speculated that the blood-vessel improvements were likely due to decreased inflammation. Participants with the poorest endothelial function at the start of the study showed the greatest apparent benefit from the olive oil. Those also receiving EGCG showed no additional benefit, however, compared to olive oil alone.
Tufts Blumberg comments, “Part of the reason the EGCG (a demonstrated anti-inflammatory and vasodilating polyphenol) may not have shown additive or synergistic actions in this study is that a threshold amount of phenols were already present in the olive oil. However, the design of this study appears not to have included an EGCG-only treatment arm that would have provided this insight.”
SMART SUBSTITUTIONS. Given their findings about olive oil, researchers concluded, “Supplementation with olive oil seems a reasonably easy and relatively cheap dietary measure to improve the endothelial function and perhaps favorably alter the progression of atherosclerotic disease, particularly in patients with already markedly impaired endothelial function.”
Before you start adding olive oil to every meal, though, Blumberg adds a caution: “I do feel it is important to note that 30 milliliters of olive oil contains 240 calories.”
Better, in short, to substitute olive oil for other fats youre already using. Try olive oil on bread instead of butter, use it in salad dressings, and drizzle it over pastas instead of serving a creamy, high-calorie sauce. You can even substitute olive oil for milk, cream and butter when making mashed potatoes. (Olive oil, especially extra-virgin oil, has a low smoke point so its not suitable for high-temperature sauting or frying.)
For a complete guide to healthy oils for cooking and other uses, see our November Special Report.