Feeding in asthma
IT IS common, knowledge that particles like pollen, moulds, dust mites and animal dander set off asthma attacks in susceptible people, but now a new study establishes the link between food allergies and respiratory problems.
The study was conducted at the Johns Hopkin Children's Centre in Baltimore, Maryland, us, where responses of 26 children with asthma and known food allergies were examined. The research team led by Hugh A Sampson, expert in paediatric allergies, found that these children may fail to respond well to asthma treatment till they stop consuming the allergic foods.
When children were fed with food known to cause allergic reactions, 12 of the 26 developed respiratory symptoms like coughing, wheezing and a tightening of the chest, and seven of them developed a hyper responsive or irritable airway, a common start to an asthma attack. The children studied were allergic to common food allergens like cow's milk, eggs, wheat, soya and fish.
There have been previous studies which have made this asthma-food con- nection, but this is the first which used lung-function to test the actual changes in the children's airways when they had consumed allergy-causing foods.
Sampson suggests that children who do not seem to respond to medication for asthma should be tested for food allergies. Such tests involve placing the child on a highly restrictive diet and then reintroducing the allergic foods one by one. When deciding which children were to be tested, the researchers chose those who had a history of skin rashes and those whose parents thought that eating a particular food made the asthma worse.
In 1988, Elio Novembre and his colleagues from the University of Florence in Italy, conducted a study on 140 children with asthma. They reported that after consuming allergy-provoking foods, 13 of the children had respiratory symptoms and eight had an asthmatic reaction.
Another study conducted the same year reported that allergies linked to inhaled substances led to a decline in lung function later in life. Under Daniel J Gottlieb, Boston University Medical Centre researchers studied 1,035 men who did not have asthma and who were around 61 years in age. They were given lung function and skin allergy tests and then three years later they were tested once again. It was found that people with allergic reactions to one or more airborne allergens were more likely to experience a decline in lung function than men who were riot allergic. Suggests Gottlieb, "allergy may be one factor that predisposes people to chronic obstructive pulmonary disease", emphysema and chronic bronchitis as they get older.
The main cause of asthma is cigarette smoking, though attacks may occur due to airborne allergens independent of smoking. Findings suggest that people with inhalant allergies may avoid chronic respiratory disease in the later part of life if they receive proper medical treatment to control their allergies and avoid smoking.