A study published on Monday on the benefits of a "Mediterranean diet", which is high in fruit, vegetables, fish and unrefined foods, found that including a higher number of these foods is linked to a lower risk of heart attack and stroke in people who already have heart disease.

A study published on Monday on the benefits of a "Mediterranean diet" found that including a higher number of these foods is linked to a lower risk of heart attack and stroke in people who already have heart disease. However the research also found that a moderate consumption of foods typical in a "Western diet," such as refined carbohydrates, deep fried foods, sugars and desserts, may not always have the negative health consequences expected.

High in fruit, vegetables, fish and unrefined foods, the "Mediterranean diet" is already well-known for its health benefits, with many previous studies showing that following a Mediterranean diet can reduce the risk of death from cancer and heart disease as well as reduce the risk of developing of Parkinson's and Alzheimer's diseases.

This new international study, carried out by a team in New Zealand, looked at 15,482 people with stable coronary artery disease and an average age of 67 in 39 countries around the world.

The participants were asked to complete a lifestyle questionnaire on their diet including how much meat, fish, dairy foods, whole grains or refined grains, vegetables (excluding potatoes) and fruit they ate on a weekly basis, considered to be part of a "Mediterranean diet," and how many desserts, sweets, sugary drinks, deep-fried foods and alcohol they also consumed, considered to be foods part of an unhealthier "Western diet."

Participants were given two scores based on their answers. Those who consumed more healthy foods were given more points on the "Mediterranean diet score" (MDS) and those who ate more unhealthy foods were given more points on a "Western diet score" (WDS).

The points ranged from 0-24.

The researchers then followed up on the participants 3.7 years later to compare how many participants from each diet group had experienced a major adverse cardiovascular event (MACE) such as heart attack, stroke or death.

They found that the higher the MDS diet score, and therefore the higher the number of healthy foods that were included in the diet, the lower the risk of MACE, with MACE occurring in 10.8 per cent of those with an MDS score of 12 or lower, 10.5 per cent of those with an MDS of 13-14, and decreasing even further to 7.3 per cent of those with an MDS score of 15 or over.

The team found that these results were consistent across every country included in the study.

Surprisingly the team also found no evidence to suggest that consuming a higher number of unhealthy foods typical of a "Western Diet" caused an increase in MACE, with results suggesting that including more healthy foods in the diet was more important than avoiding unhealthy foods.

However lead author Professor Ralph Stewart warned that the findings did not mean that people could consume unhealthy foods freely, with the study's limitations making it difficult to assess exactly what the harm of these unhealthy foods may be, concluding that "The main message is that some foods -- and particularly fruit and vegetables -- seem to lower the risk of heart attacks and strokes... If you eat more of these foods in preference to others, you may lower your risk."

The findings were published in the European Heart Journal.