A diet rich in vegetables, such as tomatoes and aubergines, and fish can help cut asthma and allergy incidence in children, a study suggests.
Researchers from the Department of Social Medicine at the University of Crete, Greece, and writing in the journal Pediatric Allergy and Immunology, studied the diet of 460 Spanish children.
They discovered that children who consumed more than 40 grams of "fruity vegetables" a day - namely tomatoes, aubergines, cucumber, green beans and courgettes - were much less likely to suffer from childhood asthma.
And children who consumed more than 60 grams of omega-3 containing fish daily also suffered less childhood allergies.
The study adds to a body of evidence supporting the health benefits of omega-3 and a diet high in vegetables. Dietary omega-3 has also been linked to having an anti-cancer effect as well as offering Alzheimer's protection.
This is not the first time a diet rich in "fruity vegetables" has been linked to having the potential to reduce the risk of respiratory conditions like asthma, chronic bronchitic symptoms, and wheeze. However, this study claims to be unique because it assessed maternal dietary habits during pregnancy as well as children's dietary habits.
Lead author Dr Leda Chatzi said: "Because we studied the children from pregnancy to childhood, we were able to include a wide range of elements in our analysis, including maternal diet during pregnancy, breastfeeding, smoking, the mother's health history, parental education and social class."
Researchers followed the progress of the children, on the Spanish island of Menorca, at regular intervals from before they were born until they were six-and-a-half.
Rich servings of fish and vegetables are also found in the Mediterranean diet, which too has been linked to a wealth of health benefits, such as helping Alzheimer's disease sufferers to live longer.
Fruits and vegetables are rich sources of antioxidant vitamins such as vitamins C, E and carotenoids, and other antioxidants such as selenium and flavonoids, that are thought to reduce airway inflammation by protecting airway cells from endogenous and exogenous oxidative damage, the researchers said.
They found that when an average daily intake was relatively high for fruits (177 g) and fish (54 g), and moderate for vegetables (59 g) a "beneficial effect" was found on respiratory conditions.
They added: "When we simultaneously included fruity vegetables and fish intake in the multivariate models, results remained very similar, showing an independent beneficial effect on the prevalence of atopy and wheeze."
However, they found that no other fruits or vegetables were significantly associated with wheeze or allergy prevalence.
Dr Chatzi added: "The biological mechanisms that underlie the protective affect of these foods is not fully understood, but we believe that the fruity vegetables and fish reduce the inflammation associated with asthma and allergies."
Source: Pediatric Allergy and Immunology
Diet, wheeze, and atopy in school children in Menorca, Spain
Authors: Leda Chatzi1, Matias Torrent, Isabelle Romieu, Raquel Garcia-Esteban, Carlos Ferrer, Jesus Vioque, Manolis Kogevinas and Jordi Sunyer.