A proinflammatory diet has detrimental effects on wheeze in adults and in children with atopy according to the results of a study published in the Journal of Allergy and Clinical Immunology Practice.
Yueh-Ying Han, PhD, of the Division of Pediatric Pulmonary Medicine, Allergy, and Immunology at the Children’s Hospital of Pittsburgh in Pennsylvania and colleagues analyzed data from 8175 children and 22,294 adults who participated in the 2007 through 2012 National Health and Nutrition Examination Survey to determine the relationship between the diet’s inflammatory potential as measured by the Dietary Inflammatory Index (DII) and current asthma, current wheeze, and lung function.
The DII establishes inflammatory profiles of various foods according to whether they increase, decrease, or have no effect on 4 established proinflammatory biomarkers — interleukin (IL)1-beta, IL-6, tumor necrosis factor-alpha, and C-reactive protein — or whether they increase, decrease, or have no effect on 2 established anti-inflammatory biomarkers — IL-4 and IL-10.
Among the food parameters included in the DII, saturated fat, trans fat, and cholesterol are the main proinflammatory contributors, whereas n-3 and n-6 fatty acids have anti-inflammatory properties. In addition, nutrients derived primarily from fruits and vegetables exhibit anti-inflammatory effects and may have protective effects against allergic diseases such as asthma through downregulation of Th2 immune responses, airway inflammation, and oxidative stress.
Higher DII (a proinflammatory diet) was associated with current wheeze among adults (odds ratio [OR] for quartile 4 vs quartile 1, 1.41; Ptrend <0.01). Among children with high fractional exhaled nitric oxide, which is a marker of eosinophilic airway inflammation, the OR was 2.38 (Ptrend =0.05). The DII was also associated with decreased forced expiratory volume in 1 second and forced vital capacity in adults without asthma or wheezing. However, the DII was not associated with lung function in children or current asthma in either age group.
The authors argued that these results lend further support to testing dietary interventions as part of the management of asthma.
Han Y-Y, Forno E, Shivappa N, Wirth MD, Hébert JR, Celedón JC. The dietary inflammatory index and current wheeze among children and adults in the United States [published online February 6, 2018]. J Allergy Clin Immunol Pract. doi:10.1016/j.jaip.2017.12.029