Regularly consuming olive oil can help protect against heart disease, a new study has shown.

Researchers at Glasgow University said volunteers who took 20ml of olive oil every day for six weeks were found to have a reduced risk of coronary artery disease (CAD), the most common form of heart complaint.

The team used a new technique where urine samples were examined for altered levels of certain proteins which indicate poor heart health.

They concluded that replacing part of your everyday fat intake with olive oil, a key component of the Mediterranean diet, significantly raises the heart's protection against disease.

The beneficial effect is thought to be down to phenolics, natural compounds found in plants, including olives.

Dr Emilie Combet from the university's School of Medicine said: "What we found was that regardless of the phenolic content of the oil, there was a positive effect on CAD scores. In the population studied, any olive oil, low or high in phenolics, seems to be beneficial. The fatty acids are probably the main contributors to the observed effect.

"Our study was a supplementation study. If people in the UK replaced part of their fat intake with olive oil, it could have an ever greater effect on reducing the risk of heart disease."

The study, published in The American Journal of Clinical Nutrition, was jointly carried out by Lisbon University and Mosaiques Diagnostics in Germany.

Dr Bill Mullen from Glasgow's Institute of Cardiovascular and Medical Sciences said: "What proteomic analysis of urine can do is measure if you are at the very early stages of disease development, before any symptoms are present.

"It is the first time this technique has been applied from a nutritional perspective to try to get to the bottom of which food or what ingredient is truly responsible for health benefits.

"We have shown, for the first time, how proteomics can successfully be used to measure the health effect of food in a small study group after only six weeks.

"We believe that use of proteomic biomarkers to assess the health improvements brought about by changes in diet, and potentially exercise, could provide an incentive for people to change their lifestyle. It also provides a means of testing so-called health foods, which can be more accurately labelled to allow informed consumer choice."