Olive oil's secret in cancer fight

LONDON - Scientists have discovered why eating a Mediterranean diet rich in fruits, vegetables and particularly olive oil can help to protect women from developing breast cancer.

The key is oleic acid, the main component of olive oil.

Dr Javier Menendez, of Northwestern University Feinberg School of Medicine in Chicago, said oleic acid blocked the action of a cancer-causing oncogene called HER-2/neu found in about 30 per cent of breast cancer patients.

"We have something now that is able to explain why the Mediterranean diet is so healthy," he said.

Doctors and researchers had been aware that eating a Mediterranean diet reduced the risk of breast cancer and other illnesses such as heart disease. But until now they did not know how.

Dr Menendez and his colleagues in the United States and Spain studied the impact of oleic acid in laboratory studies of breast cancer cells.

"We are able to demonstrate that the main component of olive oil, oleic acid, is able to down-regulate the most important oncogene in breast cancer," he said.

"The most important source of oleic acid is olive oil."

They found that oleic acid not only suppressed the action of the oncogene, it also improved the effectiveness of the breast cancer drug Herceptin, a therapy made by Swiss firm Roche that works against the HER-2/neu gene.

Breast cancer patients with HER-2/neu positive tumours suffer from an aggressive form of the disease and have a poor prognosis.

"There is no evidence at all that olive oil is toxic," said Dr Menendez, who reported his findings in the journal Annals of Oncology. "It is totally safe to consume olive oil."

More than one million cases of breast cancer are diagnosed worldwide each year. In 1998, the disease caused 1.6 per cent of all female deaths, according to the International Agency for Research on Cancer in Lyon, France.

The researchers are hoping to uncover the mechanism by which oleic acid targets the oncogene and are planning studies of animals with breast cancer to see if a diet high in olive oil can alter the activity of the oncogene and the impact of Herceptin.

- REUTERS