Research seems to point out that children who eat a diet high in fruit, nuts, olive oil, and vegetables; basically a Mediterranean diet, may be less likely to develop allergies and asthma. The diet helped allergic rhinitis, asthma, and skin allergies. Children who ate nuts at least three times a week, as well as grapes, were less likely to have asthmatic symptoms. Interestingly, lots of margarine greatly increased asthma and allergic rhinitis.
Some of the experts and researchers feel that the enormous increase of asthma in developed countries is linked to eating less natural and fresh foods to fast foods the last few decades. Asthma rates have doubled in the last 20 years while there has been a decrease in important vitamins and minerals in children's diets. At the same time the consumption of fats in oils and processed foods has risen dramatically.
High consumption of a 'Mediterranean' diet consisting of fruit, vegetables, whole grains, legumes, nuts and olive oil had a positive effect, says a report by researchers from Crete, Britain and Spain. Eating oranges, apples, grapes, and tomatoes daily protected against wheezing and allergic rhinitis. Nuts were very beneficial, possibly because they contain vitamin E and high levels of magnesium, which may protect against asthma.
Also research at St George's Hospital Medical School in London found that healthy lung function was linked to high intake of vitamins C, E, beta-carotene, and citrus fruits, apples and fruit juice. High levels of antioxidants in the diet like C and E help people handle inflammatory lung disease better. Also it is possible that high intake of salt and fatty acids like those found in margarine could induce asthma.