Eating more vegetables, fruits, nuts, pulses and olive oil, and drinking moderate amounts of alcohol, while not consuming a lot of meat or excessive amounts of alcohol is linked to people living longer.

However, the study also claims, that following a Mediterranean diet high in fish, seafood and cereals and low in dairy products were not indicators of longevity.

While several studies have concluded that the Mediterranean diet improves chances of living longer, this is the first to investigate the importance of individual components of the diet.

Professor Dimitrios Trichopoulos at the Harvard School of Public Health explains that they have surveyed over 23,000 men and women who were participants in the Greek segment of the European Prospective Investigation into Cancer and Nutrition (EPIC).

Participants were given dietary and lifestyle questionnaires when they enrolled onto the study and they were subsequently followed up for around 8.5 years with interviews. Their diets were rated from 0 to 10 based on the level of conformity to a traditional Mediterranean diet.

As part of the interview process, participants were also asked about their smoking status, levels of physical activity and whether they had ever been diagnosed with cancer, diabetes and heart disease.

The authors maintain that when high intake of vegetables, low intake of meat or moderate alcohol intake were excluded from the rating system, the benefits of following a Mediterranean diet were substantially reduced. They also note that there are clear benefits in combining several of the key components, for example high consumption of vegetables and olive oil.

Professor Trichopoulou, lead author of the study, concludes that the main reasons why the Mediterranean diet can lead to living longer are moderate consumption of ethanol (mostly in the form of wine during meals, as traditionally done in the Mediterranean countries), low consumption of meat and meat products, and high consumption of vegetables, fruits and nuts, olive oil and legumes.

Adapted from materials provided by BMJ-British Medical Journal.