A Mediterranean diet could prevent childhood asthma

A study carried out on the Greek island of Crete found eating high quantities of traditional foods such as olive oil could protect youngsters from wheezing and other allergic symptoms.

Researchers found eight out of 10 children ate fresh fruit - and over two thirds of them fresh vegetables - at least twice a day.

The effect of diet was strongest on allergic rhinitis which results in a runny or blocked nose, but it also gave protection against asthma symptoms and skin allergies.

Children who ate nuts at least three times a week were less likely to wheeze, as well as those who enjoyed grapes.

But high consumption of margarine doubled the chances of asthma and allergic rhinitis, says a report published in the medical journal Thorax.

Experts believe the epidemic of asthma in developed countries could be linked to a move away from natural, fresh foods to fast foods - as has happened here since the 1970s.

Asthma rates in the UK have doubled in the last 20 years at the same time as there has been a steady decline in key vitamins and minerals in children's diets, while consumption of fats in oils and processed foods has soared.

Over 1.4 million British children have asthma and rates have shot up four-fold since the 1970s.

In recent years the Mediterranean diet has been thought to improve heart health and stave off cancer because it is high in fruit, vegetables, fish and 'healthy' fats such as those in olive oil, while low in red meat and dairy products.

The latest study looked at 700 children aged between seven and 18 years living in four rural areas of Crete.

Although skin allergies are quite common on the island, respiratory allergies such as asthma and allergic rhinitis are relatively rare.

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

They were quizzed about whether the children ate a 'Mediterranean' diet consisting of fruit, vegetables, whole grains, legumes, nuts and olive oil.

High consumption of these foods had a protective effect, says a report by researchers from Crete, Britain and Spain.

A daily diet of oranges, apples and tomatoes protected against wheezing and allergic rhinitis, as well as grapes.

Nuts were particularly beneficial, probably because they contain vitamin E, the body's primary defence against cellular damage, and high levels of magnesium, which may protect against asthma and boost lung power.

"Our findings indicate that a high dietary intake of commonly consumed fruit and vegetables and nuts may have a protective role on the prevalence of asthma-like symptoms and allergic rhinitis" says the report.

The research 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.

Experts believe children could be made more vulnerable to allergies through dietary deficiencies either in the womb or in early childhood.

For example, a shortage of vitamins C and E in the mother's diet may be lowering the defences in newborn babies' lungs, making them more prone to allergic sensitisation.

Previous research from a team at St George's Hospital Medical School, London, found good lung function was linked to high intakes of vitamins C, E and beta-carotene, citrus fruits, apples and fruit juice.

Researchers say high levels of antioxidants in the diet - such as vitamins C and E - help people deal more effectively with inflammatory lung disease.

It is thought that high intake of salt and fatty acids - such as those found in margerines - could also induce asthma.

Dr John Moore-Gillon, president of the British Lung Foundation, said "Five million people in the UK have asthma – 1.4 million of them are children under the age of 16. "Asthma leads to 74,000 hospital admissions each year and can cause such severe attacks of breathlessness that people cannot speak and fear they may die.

"Anything that furthers our understanding of this debilitating disease is to be welcomed, and we will be looking very carefully at this research."

Leanne Male, Assistant Director of Research at Asthma UK charity, said "The results of this study add to the existing evidence which indicates that a healthy diet can play an important role in the control of asthma symptoms.

"The results demonstrate that the Mediterranean diet, which traditionally contains higher levels of fresh fruit and vegetables, can have a beneficial effect on asthma symptoms in children.

"This benefit is thought to be linked to the vitamins and antioxidants which they contain and Asthma UK is currently funding a number of research projects to further explore this association.

"5.2 million people in the UK currently have asthma, and one in ten children are affected.

"Therefore Asthma UK encourages all children and adults with asthma to lead a healthy lifestyle, which includes eating plenty of fresh fruit and vegetables, as this may help with the control of their asthma symptoms."