Eating food fried in olive or sunflower oil is not linked to heart disease or premature death, finds a paper published in the British Medical Journal online (bmj.com).

The authors stress, however, that their study took place in Spain, a Mediterranean country where olive or sunflower oil is used for frying and their results would probably not be the same in another country where solid and re-used oils were used for frying.

In Western countries, frying is one of the most common methods of cooking. When food is fried it becomes more calorific because the food absorbs the fat of the oils.

While eating lots of fried food can increase some heart disease risk factors such as high blood pressure, high cholesterol and obesity, a link between fried food and heart disease has not been fully investigated.

So the authors, led by Professor Pilar Guallar-Castillón from Autonomous University of Madrid, surveyed the cooking methods of 40,757 adults aged 29 to 69 over an 11-year period. None of the participants had heart disease when the study began.

Trained interviewers asked participants about their diet and cooking methods. Fried food was defined as food for which frying was the only cooking method used. Questions were also asked about whether food was fried, battered, crumbed or sautéed.

The participants' diet was divided into ranges of fried food consumption, the first quartile related to the lowest amount of fried food consumed and the fourth indicated the highest amount.

During the follow-up there were 606 events linked to heart disease and 1,134 deaths.

The authors conclude: "In a Mediterranean country where olive and sunflower oils are the most commonly used fats for frying, and where large amounts of fried foods are consumed both at and away from home, no association was observed between fried food consumption and the risk of coronary heart disease or death."

In an accompanying editorial, Professor Michael Leitzmann from the University of Regensburg in Germany, says the study explodes the myth that "frying food is generally bad for the heart" but stresses that this "does not mean that frequent meals of fish and chips will have no health consequences." He adds that specific aspects of frying food are relevant, such as the type of oil used.