One of the experimental breakfasts contained virgin olive oil with high-content phenolic compounds (398 parts per million) and the other breakfast contained olive oil with low-content phenolic compounds (70 parts per million). All volunteers consumed the same low-fat, carbohydrate rich "background" diet during both study phases.

The researchers tracked the expression of more than 15,000 human genes in blood cells during the after-meal period. The results indicated that 79 genes are turned down and 19 are turned up by the high-phenolic-content olive oil. Many of those genes have been linked to obesity, high blood-fat levels, type 2 diabetes and heart disease. Importantly, several of the turned-down genes are known promoters of inflammation, so those genes may be involved in "cooling off" inflammation that often accompanies metabolic syndrome.

The researchers concluded that the results shed light on a molecular basis for reduced heart disease risk among people living in Mediterranean countries where virgin olive oil is the main source of dietary fats.

Source: United States Department of Agriculture-Research, Education, and Economics