Eating a "Mediterranean-style" healthy diet could help protect children from respiratory allergies and asthma, research finds.

The Mediterranean diet is characterised by a high intake of vegetables, legumes, fruits, and cereals and a moderate to high intake of fish.

It also includes a low intake of saturated fats, but high intake of unsaturated fats, particularly olive oil, and a low intake of dairy products and meat, and a modest consumption of alcohol, mostly wine.

UK, Greek and Spanish researchers assessed the dietary habits, respiratory symptoms, and allergic reactions of almost 700 children living in four rural areas on the Greek island of Crete.

The children were all aged between 7 and 18 years of age.

Skin allergies are relatively common in Crete, but respiratory allergies, such as asthma and allergic rhinitis, are relatively rare.

Parents completed questionnaires on their children's allergic and respiratory symptoms and dietary habits.

Whether the children ate a Mediterranean diet was measured against a set of 12 foodstuffs, including fruits, vegetables, whole-grains, legumes, nuts and olive oil.

Eight out of 10 children ate fresh fruit and over two thirds of them ate fresh vegetables, at least twice a day.

The effect of diet was strongest on allergic rhinitis, but it also afforded protection against asthma symptoms and skin allergy.

Children who ate nuts at least three times a week were less likely to wheeze.

Nuts are a rich source of vitamin E, the body's primary defence against cellular damage caused by free radicals.

They also contain high levels of magnesium, which other research suggests, may protect against asthma and boost lung power.

The study, which is published in Thorax, also found that a daily diet of oranges, apples, and tomatoes protected against wheezing and allergic rhinitis.

Grapes in particular seemed to protect against current and previous wheezing and allergic rhinitis.

Red grape skin contains high levels of antioxidants as well as resveratrol, a potent polyphenol, known to curb inflammatory activity.

But high consumption of margarine doubled the chances of asthma and allergic rhinitis, the study revealed.

The study was carried out by researchers at the Royal Brompton Hospital, in London, the University of Crete, Venezelio General Hospital in Crete and the Centre for Research in Environmental Epidemiology, in Barcelona.