Children who started eating fish before 9 months of age are less likely to suffer from pre-school wheeze, but face a higher risk if they were treated with broad spectrum antibiotics in the first week of life or if their mother took paracetamol during pregnancy, according to the findings of a large-scale Swedish study published in Acta Paediatrica.
Researchers analyzed responses from 4,171 randomly selected families, who answered questions when their child was 6 months, 12 months and 4.5 years of age.
The study examined children who had had three or more episodes of wheezing in the last year, including those who did and did not use asthma medication (inhaled corticosteroid), comparing them with children who did not wheeze. The wheezy sample was further broken down into children who only developed episodic viral wheeze when they had colds and multiple trigger wheeze, where children also wheezed when they didn’t have a cold, reacting to factors such as allergens, tobacco smoke or exercise.
The researchers found that one in five of the children had at least one episode of wheezing and one in 20 had recurrent wheeze (three or more episodes) over the last year. Of these, three-quarters had used asthma medication and just over half reported doctor-diagnosed asthma. More than half of the children with recurrent wheeze had episodic viral wheeze (57%) and 43% had multiple-trigger wheeze.
Additionally, the findings showed that eating fish before the age of 9 months almost halved the likelihood of suffering recurrent wheeze at 4.5 years. The fish most commonly eaten was white fish, followed by salmon and flat fish. Previous studies reported that fish, which is thought to contain properties that reduce allergy risks, is beneficial in both eczema in infancy and allergic rhinitis at pre-school age. Other research has suggested a protective effect on the development of asthma.
The researchers also noted that being treated with broad-spectrum antibiotics in the first week was associated with double the risk of recurrent wheeze at 4.5 years. Just 3.6% of the children in the no wheeze group had received antibiotics, compared with 10.7% of those who had experienced three or more episodes. When this was broken down into subgroups, the risk was even higher in children with multiple-trigger wheeze, while the risk of episodic viral wheeze was not statistically increased.
The study further showed that less than a third of the mothers (28.4%) had taken some medication during pregnancy, 7.7% taking paracetamol; while 5.3% reported only taking paracetamol. The prevalence of prenatal paracetamol exposure in the wheeze group using asthma medication was 12.4% and taking paracetamol during pregnancy increased the risk by 60%. The effect was particularly noticeable in the multiple-trigger wheeze group, where it more than doubled the risk.
"The aim of this study was to determine the risk factors for pre-school wheeze, with particular reference to prenatal paracetamol use, early exposure to antibiotics, and fish consumption. A secondary aim was to analyze possible differences between multiple-trigger wheeze and episodic viral wheeze,” said Emma Goksor, lead author from Queen Silvia Children’s Hospital, University of Gothenburg, Sweden. "Our findings clearly show that while fish has a protective effect against developing pre-school wheeze, children who had antibiotics in the first week of life and whose mothers took paracetamol during pregnancy faced an increased risk, particularly of multiple-trigger wheeze."