Asthma and atopy – the price of affluence?

Abstract

Irrespective of improved knowledge of many aspects of atopic diseases, the unfavorable trends in their prevalence particularly among children could not have been reversed. A growing body of evidence suggests that something may lack from our societal affluence that has the capacity to provide protection against the development of atopic diseases. Much attention during the last years has been devoted to the hygiene hypothesis. This review outlines the impact of environment and lifestyle, particularly from the perspective of the East–West gradient, on the development of atopic diseases, with a special emphasis on the hygiene hypothesis in its broadest sense.

The causes of asthma: the need to look at the data with different eyes

“…A new one is proposed in the present issue by Wjst, suggesting that either the increased survivability of children with a TH1 maturation defect or the lack of a Th1 environmental trigger may play a role in the increased trends of allergy and asthma (5). The comprehensive review by von Hertzen and Haatela (6) in this issue of Allergy illustrates how many potentially relevant hypotheses about the determinants of asthma are being investigated. Their notion that something is lacking from our affluent societies that has the capacity to protect against the development of atopic (and autoimmune) diseases is like a paradox of the current immoral worldwide distribution of health and wealth.…”

“…However, while research on lung cancer led to the now uncontroversial evidence that lung cancer is mainly caused by smoking cigarettes, this has not been the case with asthma, where nearly two decades of intense research has neither provided robust evidence nor any widely accepted answer about its origins. This issue of Allergy features a remarkable quartet of reviews focusing on different issues of asthma (3)(4)(5)(6). While these four reviews provide a very valuable update on current knowledge about the determinants of asthma, they also show the lack of well established answers.…”

Association between obesity and asthma – epidemiology, pathophysiology and clinical profile

“…This rapid increase, with clearly observable social and demographic patterns, again suggests changes in lifestyle to be a possible explanation (14) .…”

Ramp-ing up allergies: Nramp1 (Slc11a1), macrophages and the hygiene hypothesis

“…In general, three infectious candidates have received attention in the hygiene hypothesis (reviewed in Refs [9,10]): oro-faecal infections or gut commensals, helminths and mycobacteria. The candidature of mycobacteria was derived from experiments in animal models, in which bacillus Calmette-Guérin (BCG) or heat-killed Mycobacterium vaccae significantly reduced allergic and asthmatic manifestations [11,12].…”