Virgin olive oil may better protect against heart disease than more refined olive oils, suggests a recent European study published in the Annals of Internal Medicine (2006, vol. 145, no. 5). Drawn from the first pressing of olives, virgin oil packs higher levels of polyphenols, antioxidants thought to increase beneficial high-density lipoprotein (HDL) cholesterol levels and help prevent oxidation of harmful low-density lipoprotein (LDL) cholesterol. Researchers served 200 healthy men 25 ml—approximately 11/2 tablespoons—of either virgin olive oil, refined olive oil, or a mixture of the two every day for 21 days. Two weeks later, the polyphenol-rich virgin oil had increased participants' HDL levels more significantly than the other oils, making virgin olive oil a more potent protector against heart disease.