Just a little olive oil

Olive oil has a well-deserved reputation for helping to reduce the risk of heart disease. Most of that reputation is from research into the Mediterranean Diet, so named because it is a collection of dietary habits followed by those in the region of the Mediterranean Sea (see our article on the Mediterranean Diet for more details).

Certainly it would be ideal if everyone could follow the Mediterranean Diet, but it's unrealistic to think that people can make these changes quickly. Lots of factors influence a region's diet, from ethnicity, religion, availability of fresh foods at different times of the year, and more. A group of European scientists decided to investigate just one small change and how that might affect people from various parts of Europe (J Nutr 2007; 137:84-87).

They recruited 160 healthy men between the ages of 22 and 44 whose Body Mass Index was below 30 (which is considered clinically obese) and were not on any heart or cholesterol medications. They were separated into three groups divided by the region they were from: Northern Europe (Finland and Denmark), Central Europe (Germany) and Southern Europe (Spain and Italy).

The study tested the effect of daily intake of about a tablespoon of three different olive oils. These olive oils contained low, medium, or high levels of polyphenols, the vegetable compounds that are thought to make olive oil so effective. There were three testing periods: For three weeks each group of men took a daily dose of one of the three types of olive oils in addition to their regular diet, then there was what is known as a "washout period" of two weeks during which they did not have the supplemental olive oil.

After each testing period the subjects' blood pressure was taken, their blood was drawn and their cholesterol levels checked. The most significant results in those men who did not already follow a Mediterranean Diet (presumably those men from Northern and Central Europe) was a reduction in systolic blood pressure (the top number and the one that's often of more concern). Cholesterol scores were also improved in those men who tried to adjust for the additional fat in the olive oil by reducing the fat they consumed in other foods.

What this means for you

It's easier to stick with small changes in your diet, and this study shows just how much of an effect such small changes can have. Instead of using butter (or worse, margarine), use olive oil for searing or pan-frying.

First posted: January 19, 2007