"The results of the present study suggest that dietary modification or supplementation during pregnancy to reduce the likelihood of childhood asthma warrants further investigation," said Dr. Graham Devereux from the University of Aberdeen.
According to the European Federation of Allergy and Airway Diseases Patients Association (EFA), over 30m Europeans suffer from asthma, costing Europe €17.7bn every year. The cost due to lost productivity is estimated to be around €9.8bn.
The researchers analysed a cohort of 1,861 children born to women recruited during pregnancy and followed for 5 years. Data on asthma symptoms and dietary intakes from food frequency questionnaires were available for 1,253 and 1,120 children, respectively.
According to the authors, children born to mothers from the lowest quintile of vitamin E intake were over five times more likely to manifest early persistent asthma than children whose mothers were in the highest quintile.
It was also found that increasing blood levels of alpha-tocopherol, the most abundant form of vitamin E in the diet, was associated with better lung function - every microgram per millilitre increase in alpha-tocopherol in the mother's blood was associated with a seven millilitre increase in lung capacity measurements.
The study cited vegetable oils (sunflower, rapeseed and corn), margarine, wheat germ, nuts and sunflower seeds as major food sources of vitamin E for mothers in the U.K.
Low maternal zinc intake during pregnancy was also linked to an increased risk of asthma in the offspring.
"Our findings suggest that vitamin E has a dual effect on lung function and airway inflammation and that the effects could change at differing periods of prenatal and early life," said Dr. Devereux.
"Lung function was associated with early vitamin E exposure independent of atopy, whereas allergic airway inflammation was associated with vitamin E exposure in later pregnancy."
The child's dietary intake of specific nutrients were not linked to respiratory health, reported the researchers in the American Journal of Respiratory and Critical Care Medicine (Vol 174, pp. 499-507).
"The present study suggests that children's own nutrient intake at the age of five does not modify the associations between maternal nutrient intake and respiratory outcomes in the children," said Devereux.
Increasing levels of allergies, such as asthma, have led to increased research into the possible benefits of diet on such conditions. Recently, two reports have been published noting that higher intake of fruit and vegetables could reduce the risk of asthma in adulthood (Thorax, Vol. 61, pp. 209-215, and Vol. 61, pp. 388-393).
These study add to a growing body of science that has linked antioxidant intake, particularly vitamins C and E, to the incidence of asthma, a condition on the rise in the Western world and the most common long-term condition in the UK today.