And so, after many decades of implicating fast-foods as the root cause, directly or indirectly, of a multitude of ills, there’s a possible new set of ailments to be added to the burgeoning list . . . .
The conclusions are drawn from the third phase of the International Study of Asthma and Allergies in Childhood (ISAAC). The comprehensive review was initiated in 1991 and involved 56 countries, 181,632 children aged 6 and 7 and 319,196 adolescents aged 13 and 14. The key findings and conclusions were reported by the principle investigator, Dr P. Ellwood of the Department of Paediatrics in the University of Auckland, in the peer-reviewed journal Thorax (1).
A number of food types were studied across both age groups and included, amongst others:
Whilst with some foods, there was no clear association between the level of intake and the three disorders, statistically significant links were seen in both children and adolescents between fast-food consumption, 3 times a week and an increased risk of developing a severe form of any one of the three principle conditions. It was also noted in the adolescent group, that a similar outcome resulted from eating butter, margarine or pasta at least 3 times a week.
Interestingly, however, the study also revealed that some foods appeared to have a ‘protective’ effect. For example, the intake of fruit and vegetables at least 3 times a week reduced the risk of the development of the severe forms of eczema, asthma or rhinoconjunctivitis in the children’s group. Eating vegetables once or twice a week was also identified as providing some benefits in the adolescent group as a consequence of an observed lower incidence of severe eczema.
In the report, the authors conclude,
“….. fast-food consumption may be contributing to the increased prevalence of asthma, rhinoconjunctivitis and eczema in adolescents and children. ….. diets that have a regular consumption of fruit and vegetables are likely to protect against asthma, allergic diseases and other non-communicable disease.”
But the study results and conclusions come with a warning of potential misinterpretation and the limitations are indeed acknowledged by the authors. Although enlisting more than half a million participants, the evaluation was not conducted within the strict formal structure of a classical randomised clinical trial which may have offered factual evidence of an apparent linkage between fast-food intake and the subsequent development of severe eczema, asthma or rhinoconjunctivitis. It is possible that there could be other conditions and circumstances such as the quality of a child’s living standards, parenting, or economic status which have more of a direct influence in placing children and adolescents at increased risk. It is possible – although highly unlikely, that adolescents with eczema happen to indulge in fast-foods, more than their healthy study participants. And which came first – the fast-food or the eczema? The study doesn’t record any of this data or other potential influencing conditions.
What is certain is that there is now a real need to conduct a full randomised trial to confirm or refute the findings. The reported significant increase in the prevalence of asthma and eczema in children and adolescents in recent years is a major cause for concern. All efforts, such as the ISAAC study, in attempting to understand the aetiology of these diseases are an essential component of the drive to finding preventative and corrective solutions.
1. Ellwood P, et al, Thorax 2013 Apr; 68(4):351-60