Bottomline: A study on over 25,000 school-aged kids shows eating higher amounts of the omega-6 fatty acid, linoleic acid, increased risk of asthma.  Clin Exp Allergy. 2008 Oct;38(10):1644-50.

Background: There is a worldwide rapid rise in the prevalence of asthma which is not explained by genetics.  Different studies on children in Italy, Spain, Greece and Australia have implicated the increase of dietary omega-6 fats as a possible reason for increased asthma or wheezing.  When the omega-6 fat, arachidonic acid combines with the LOX enzyme, it creates one of the most potent compounds that wreak inflammation havoc on the lungs, the leukotriene B4.

Summary:  Dietary habits of over 25, 000 children from Okinawa, Japan were evaluated over a period of one month using a food frequency assessment. Symptoms of wheeze and asthma were evaluated according to diagnostic criteria from the International Study of Asthma and Allergies in Childhood.   Intake of linoleic acid was independently associated with  an increased prevalence of wheeze after allowance for confounding factors.

The results of this study are consistent with findings from other researcher.  For example, Eating margarine (a food high in omega-6 fat) was significantly related to the prevalence of wheeze among Italian children.  A nested case-control study among Australian children showed a significant association between the prevalence of omega-6 fat in the diet and the risk of asthma.

Comment: Notably, this population of kids in Japan, eat a high fish diet, rich in omega-3 fats.  A recent study (Castro-Rodguez), showed that a Mediterranean diet, which is typically low in omega-6 fat, was protective against wheezing, independent of physical activity and obesity.

Links to Studies:
Castro-Rodriguez JA et al.
Mediterranean Diet as a Protective Factor for Wheezing in Preschool Children. J Pediatr 2008;152:823-828.

Miyake Y, Sasaki S, Arakawa M, Tanaka K, Murakami K, Ohya Y.
Fatty acid intake and asthma symptoms in Japanese children: the Ryukyus Child Health Study.
Clin Exp Allergy. 2008 Oct;38(10):1644-50.

Oddy WH, de Klerk NH, Kendall GE, Mihrshahi S, Peat JK.
Ratio of omega-6 to omega-3 fatty acids and childhood asthma. J Asthma. 2004;41(3):319-26.

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