Science Update

New Study Investigates the Impact of Dietary Histamine Intake in Children with Asthma

Asthma has become more prevalent during the past decade. Many patients have managed their asthma with medication while avoiding environmental triggers.

Previous researchhas demonstrated that diet can play a significant role in the development and symptoms of asthma. Histamine is an inflammatory mediator that has been associated with inflammation in asthma patients, but its exact impact is not clear because the histamine content of foods can vary significantly by a product’s maturity, time in storage, and processing. In addition, it is important to note that histamine-secreting bacteria have been found at a higher frequency in stool samples of asthmatic patients.

 According to a new study published last week in Nutrients, researchers investigated the effect of controlling dietary histamine intake and its impact on respiratory symptoms in children with asthma. The randomized crossover, dietary intervention, two-period study included 18 children (10 boys and 8 girls) with mild-to-intermittent asthma. The research team investigated the impact of dietary histamine intake on asthma symptoms. Each child was randomized to either a high- or low-histamine diet for an 8 week-period. After a 2-week washout period, each child was switched to the opposite diet for 8 weeks. Foods were ranked according to their histamine content, and a dietitian advised parents to select foods specifically from the food list provided. Dietary intake was assessed from eight random 24-hour recalls with Food-Processor Nutrition Analysis Software. Asthma symptoms were assessed at baseline and after each diet period. Daily symptom scores and peak flow were recorded throughout the diet. The best records from three mornings and evenings of the Peak Expiratory Flow Rates (PEFRs) were measured (by flow meter) and recorded on food diary cards.

The results indicated a significantly higher air flow obstruction and an increase in disease severity after the high-histamine diet compared with less symptoms and more symptom-free days during the low-histamine diet. This study demonstrates that diet can have a direct impact on asthma symptoms. 

The pathophysiology of asthma is multifactorial, as with many chronic diseases. Therefore, several nutrients should be considered for dietary intake to modulate the underlying dysfunction and immune response. 

 Previous research has demonstrated that Lactobacillus supplementation improves asthma severity. All individuals receiving Lactobacillus-containing probiotics had lower asthma severity and higher Childhood Asthma Control Test (C-ACT) scores. In addition, the group that received both Lactobacillus strains demonstrated increased peak expiratory flow rates and lower Immunoglobulin E levels. 

Low serum vitamin D levels have also been linked to an increased risk of asthma. In a previous study published in the journal Allergy, it was demonstrated that sufficient vitamin D levels could help manage asthma attacks. Asthma patients who had a vitamin D deficiency were 25% more likely than other asthmatics to have at least one flare-up in the recent past.

We know that vitamin D has significant immunomodulatory effects, and it has been shown to have an effect on asthma. Vitamin D has been shown to promote T-regulatory cells, and it has been proposed as one of the causes of the increased prevalence of asthma.

Other nutrients to consider that support lung health and promote a healthy inflammatory response include fish oil, magnesium, vitamin C, and curcumin. 

By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS