Moderate intake of olive oil is successful in reducing the blood pressure of healthy men who don't usually stick to a Mediterranean diet, suggests a new study published in the Journal of Nutrition and reported in www.foodnavigator-usa.com.

Yet another study, also reported by www.foodnavigator-usa.com, states that virgin olive oil, a rich source of polyphenols, is the best vegetable oil for heart health. The results of the Eurolive study, published in the Annals of Internal Medicine, may convince health-conscious consumers to continue to pay more for these benefits, after a drop of 35 per cent for last year's olive crop drove prices up to record highs.

The interest in olive oil, a key part of the Mediterranean diet, has increased significantly in recent years on the back of studies linking the diet with a much lower incidence of cardiovascular disease (CVD) and certain types of cancer. Indeed, sales in the UK in 2004 alone were worth £107 million, compared with just £1 million 20 years ago, according to an AC Nielsen report.

For the study published in the Journal of Nutrition, researchers led by Isabel Bondia-Pons from the University of Barcelona, Spain, randomly assigned 110 healthy men from non-Mediterranean countries (Germany, Finland and Denmark) and 45 men from Spain and Italy to include one of three similar olive oils (25ml per day) in their diets. The cross-over trial consisted of three three-week intervention periods separated by two two-week washout periods.

The researchers report that blood levels of oleic acid increased by 2-3 per cent in the men from non-Mediterranean countries. The men from the Mediterranean countries, though, did not exhibit a significant increase in blood oleic acid levels. At the end of the nine-week intervention period, the researchers reported that the systolic blood pressure of the non-Mediterranean men decreased significantly by 3 per cent, compared to baseline measurements.

For the study published in the Annals of Internal Medicine, the researchers, led by Maria-Isabel Covas from Municipal Institute of Medical Research, Spain, randomly selected 200 male volunteers from five European nations - Spain, Denmark, Finland, Italy and Germany - and replaced their normal dietary fats with olive oil for three weeks. The brands that the researchers recommended had differing phenolic contents.

This was followed by a two-week washout period. Then there was a cross-over to one of two other dietary interventions. Covas and her co-workers observed a linear increase in high-density lipoprotein (HDL) 'good' cholesterol levels. The higher the polyphenol content of olive oil, the greater was the impact on the user's 'good' cholesterol level.