Allergies, asthma in kids linked to junk food: extensive study

An extensive study that included data from some 500,000 children, in 51 countries, resulted in a strong statistical link between eating more fast food and a 39 percent higher prevalence of asthma in teenagers. Children of the ages 6 and 7 who were in the highest fast food intake category of three or more servings per week were found to have a 27 percent increased risk by the vast study published in the medical journal Thorax on January 14.

Researchers at the University of Auckland in New Zealand found that those who ate more than three servings of foods such as burgers, fries and pizza a week had more severe allergic disease symptoms like wheezing (Asthma), runny nose and watery eyes (Rhino-conjunctivitis) and itchy skin (Eczema).

On the positive side, eating three or more portions of fruit a week, below the advised three servings per day, was found to have a protective effect and reduced the risk of severe eczema and rhino-conjunctivitis by 11 percent to 14 percent.

The teenagers and parents of the six and seven year olds were questioned on the symptoms of asthma, rhino-conjunctivitis and eczema in the preceding 12 months. The researchers also asked participants about their diet and consumption of certain types of foods and the frequency of consumption was put in three categories, measured as never or occasionally, once or twice a week and three or more times a week.

The study included data from 319,000 teens of 13 and 14 years old in 51 countries and 181,000 children between the age of six and seven in 31 countries. This enabled the study to show the results were consistent in rich and poor countries, among boys and girls, and in many different societies across Europe, Africa, the Americas and Asia, and also control for other factors potentially influencing the results.

Researchers cautioned that this kind of study cannot prove a cause-and-effect relationship, but if the latest link is indeed causal then the latest findings would have a "major public health significance owing to the rising consumption of fast foods globally," the study authors Professor Innes Asher from the University of Auckland in New Zealand, and Professor Hywel Williams, from the University of Nottingham in the UK wrote in the study.

"The positive association observed here between fast food intake and the symptom prevalence of asthma, conjunctivitis and eczema in adolescents and children deserved further exploration, particularly in view of the fact that fast food is increasing in popularity around the world," the authors wrote.

Malayka Rahman, research analysis and communications officer at Asthma UK, confirms that diet may contribute to a person's risk of developing asthma and that following a healthy diet may have a beneficial effect, as other research results show.

"This research adds to previous studies that suggest a person's diet can contribute to their risk of developing asthma, and indicates the benefit of further research to determine the effects that particular food groups can have on the chances of developing asthma or the impact it may have on severity," Rahman said in a statement.

"Evidence suggests that the vitamins and antioxidants found in fresh fruit and vegetables have a beneficial effect on asthma," Rahman added. "Therefore, Asthma UK advises people with asthma to eat a healthy, balanced diet including five portions of fruit or vegetables every day, fish more than twice a week, and pulses more than once a week."