{"id":20226,"date":"2022-07-26T10:16:40","date_gmt":"2022-07-26T08:16:40","guid":{"rendered":"https:\/\/www.wjst.de\/blog\/?p=20226"},"modified":"2025-11-02T13:38:25","modified_gmt":"2025-11-02T11:38:25","slug":"parental-allergy-history-at-farms","status":"publish","type":"post","link":"https:\/\/www.wjst.de\/blog\/sciencesurf\/2022\/07\/parental-allergy-history-at-farms\/","title":{"rendered":"Parental allergy history at farms"},"content":{"rendered":"

A recent paper on the bias of farming<\/a> studies missed the healthy worker effect<\/a> although this is being \u00a0the most likely explanation.<\/p>\n

So let’s have a more detailed look at farm parents. It can be drilled down to the question if parents are also “protected” or it is more likely that some affected parents just moved away.<\/p>\n

Here are 13 studies that included information about farm parents.<\/p>\n

\"\"<\/a>
Braun-Fahrl\u00e4nder 1999<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Ehrenstein 2000<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Barnes 2001<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Wickens 2002<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Perkin & Strachan 2006<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Midodzi 2007<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Douwes 2008<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Schaub 2009<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Pfefferle 2009<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Loss 2012<\/a><\/figcaption><\/figure>\n
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Slaats 2012<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Bedolla-Barajas 2017<\/a><\/figcaption><\/figure>\n
\"\"<\/a>
Steiman 2020<\/a><\/figcaption><\/figure>\n

Unfortunately the disease definitions in these papers is sometimes vague – does history mean both parents only? Grandparents and sibs? Is the history verified?\u00a0 So it is difficult to run a formal meta-analysis here, while the message should be already clear: All except one minor study show that the farming effect is found in parents also,<\/p>\n

Again – was there already “protection” during the childhood of the parents or is it just a delayed healthy worker effect? I am going to answer this question by looking into effect propagation<\/strong> in the Ehrenstein paper<\/a> as this is one of the largest study so far.<\/p>\n

The analysis basically works by running a 2×2 table in the parental generation (a bit questionable\u00a0 as we have 2 parents) and another 2×2 table in the child generation.\u00a0 Effect should propagate as indicated by movement of observed versus expected<\/a> cases between cells. Expected are\u00a0 row sum * col sum \/ total sum.<\/p>\n

\"\"<\/a><\/p>\n

If there is any true effect, there should be a horizontal movement between parents and children, basically just less hayfever in the farming group. If there is a pseudo effect there should be a vertical movement, eg less hayfever by less allergic parents who left the farm. So judge yourself now or wait for my forthcoming paper.<\/p>\n

 <\/p>\n

Update 1 Nov 2025<\/span><\/p>\n

As the full paper is now more than 1 year under review, I have uploaded it now to a preprint server<\/a>.<\/p>\n

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 <\/p>\n

\n CC-BY-NC Science Surf , accessed 23.04.2026<\/span>\n <\/div>","protected":false},"excerpt":{"rendered":"

A recent paper on the bias of farming studies missed the healthy worker effect although this is being \u00a0the most likely explanation. So let’s have a more detailed look at farm parents. It can be drilled down to the question if parents are also “protected” or it is more likely that some affected parents just … Continue reading Parental allergy history at farms<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[3756,199,1096,1821],"class_list":["post-20226","post","type-post","status-publish","format-standard","hentry","category-asthma-allergy","tag-erika-von-mutius","tag-allergy","tag-farming","tag-hay-fever"],"_links":{"self":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/20226","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/comments?post=20226"}],"version-history":[{"count":42,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/20226\/revisions"}],"predecessor-version":[{"id":25874,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/20226\/revisions\/25874"}],"wp:attachment":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/media?parent=20226"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/categories?post=20226"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/tags?post=20226"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}