A diet rich in olive oil, fruits, vegetables and oily fish is already known to protect against heart disease.

However, now experts writing in the British Journal of Cancer have found it also cuts the risk of developing any type of cancer.

People who adopted the diet at least six ways cut their risk of cancer by 22%.

However, even those who adopted just two elements could cut their chances of developing the disease by 12%.

Examples of this could be by substantially decreasing meat intake while substantially increasing intake of legumes like beans, peas and lentils; or by substantially increasing vegetable intake and using olive oil instead of butter.

The biggest effect, resulting in a 9% reduction in risk, appeared to be from consuming more good fats, like those found in olive oil, than bad fats, like those found in chips, biscuits and cakes.

A total of 25,623 Greek people took part in the research (10,582 men and 15,041 women) over a period of eight years.

They were asked about their diet through questionnaires on 150 different types of food and drink.

Trained interviewers assisted people to fill in their questionnaires and worked out how many grams a day people were eating using 76 photographs of portion sizes.

Adherence to the Mediterranean diet was assessed using a 10-point scale, with people scoring "0" or "1" for each of nine different food groups.

People scored 1 if they ate plenty of vegetables, legumes, fruits and nuts, cereals and fish, but 0 if they ate little or none.

They also scored 1 if they ate a high ratio of good fats to bad fats.

A score of 0 was given if they had a high intake of meat and meat products, and a high intake of dairy products, but 1 if they ate little or none.

Those with a moderate alcohol intake scored 1 while those who drank too much scored 0.

The researchers found that association between diet and decreased cancer risk was stronger for women than men.

Lead author Dr. Dimitrios Trichopoulos, professor of cancer prevention and epidemiology at Harvard University, pointed out there was no one "superfood" in the diet.

"Our results show just how important diet is in cancer risk," he said.

"Of the 26,000 people we studied, those who closely followed a traditional Mediterranean diet were overall less likely to develop cancer.

"Although eating more of one food group alone didn't significantly change a person's risk of cancer, adjusting one's overall dietary habits towards the traditional Mediterranean pattern had an important effect."

The study was performed as part of the European Prospective Investigation into Cancer and Nutrition (EPIC).

Cancer Research UK's director of health information, Sara Hiom, said, "This is an important study that helps us to understand more about the simple changes a person can make to their diet to reduce their risk of cancer and improve overall health.

"Although we know that unhealthy diets generally and being overweight are important risk factors for a number of cancers, the link between individual foods or food types and cancer has been less clear.

"This research highlights the importance of maintaining a healthy balanced diet to reduce your risk of cancer.

"It shows that there are a number of things you can do, and that there is no one 'superfood' that can stop you developing the disease."

Dr. Rachel Thompson, science program manager for the World Cancer Research Fund, said, "This is an interesting study, but the best advice for cancer prevention remains to eat a healthy diet, to be regularly physically active and to maintain a healthy weight.

"Looking at all the evidence on diet, people looking to reduce their cancer risk should aim to eat plenty of wholegrains and fruits and vegetables and limit their intake of red meat, salt and energy-dense foods.

"This study shows that the Mediterranean diet may be one way of following this advice, but there are also other ways of having a healthy diet."

From the July 7, 2008, Prepared Foods e-Flash