Published online: February 6, 2018
Dietary patterns can alter immune responses and have been linked to asthma, a chronic inflammatory airway disease. A Mediterranean diet (characterized as anti-inflammatory) has been associated with lower risk of asthma and wheeze, whereas a Westernized diet (characterized as pro-inflammatory) has been associated with increased risk of asthma and wheeze. The Dietary Inflammatory Index (DII®) is a score that categorizes an individual’s diet on a continuum from the most anti-inflammatory to the most pro-inflammatory.
In an article published in The Journal of Allergy and Clinical Immunology: In Practice, Han et al examined the relation between the DII score and current asthma, current wheeze, and lung function in 8,175 children (6-17 years) and 22,294 adults (18-79 years) from the National Health and Nutrition Examination Survey (NHANES). The survey participants were asked if they had experienced wheeze or been diagnosed with asthma in the past year. Participants also underwent spirometry testing and a 24-hour dietary recall interview that was used for the DII calculation.
Adults with a higher DII (consistent with a pro-inflammatory diet) were 1.4 times more likely to have current wheeze than those with a lower DII. A higher DII was also associated with 2.4 times increased odds of current wheeze among children with high fractional exhaled nitric oxide (FeNO, a marker of eosinophilic airway inflammation). The DII was associated with decreased forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) in adults without asthma or wheeze. The DII was not associated with lung function in children or in subjects with current asthma in either age group.
Our study suggests that a pro-inflammatory diet, assessed by the DII, increases the risk of current wheeze in adults and in children with a high exhaled FeNO. These results further support studying whole-diet interventions to improve asthma and respiratory health in the United States.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.