Plant-based foods, probiotic drinks may help fight allergic asthma

Certain plant-based foods and probiotic drinks appear to be associated with reduced prevalence of allergic asthma among young Chinese adults in Singapore, according to a study.

Analysis of food frequency questionnaire (FFQ)-based dietary intake data showed that the odds of having allergic asthma were significantly lower among participants who frequently consumed (ie, most or all days) vs never or only occasionally consumed the following food groups: fruits (adjusted odds ratio [AOR], 0.47, 95 percent confidence interval [CI], 0.31–0.71; p=0.001), vegetables (AOR, 0.58, 95 percent CI, 0.35–0.99; p=0.003), pulses (AOR, 0.65, 95 percent CI, 0.47–0.89; p<0.001), and probiotic drinks (AOR, 0.69, 95 percent CI, 0.50–0.94; p<0.001). [J Asthma Allergy 2025;18:1399-1412]

When asthma was examined according to phenotype and its clinical presentations, frequent consumption of pulses showed an association with reduced odds of exacerbated allergic asthma (AOR, 0.39, 95 percent CI, 0.22–0.69; p=0.002) and the wheezy variant (AOR, 0.53, 95 percent CI, 0.35–0.69; p<0.003). Frequent probiotic drink intake was also associated with decreased odds of both cough and wheezy allergic asthma variants.

“The varying dietary associations across asthma phenotypes suggest that diet may influence asthma expression in a phenotype-specific manner,” the authors said.

However, they pointed out that dietary interventions may be more effective for managing asthma in its early stages before severe symptoms and structural changes develop. [Nutr Rev 2020;78:928-938]

“As asthma becomes more severe, factors like chronic inflammation and airway remodelling may become more dominant, potentially reducing the impact of diet on further disease progression. Environmental factors such as air pollution, allergen exposure, and respiratory infections may also play a more substantial role in driving asthma severity,” the authors explained. [J Physiol Anthropol 2021;40:22; J Clin Invest 2019;129:1504–1515]

Longitudinal studies are needed to better understand the timing and long-term effects of dietary changes on asthma progression and the development of various phenotypes, they added.

Population characteristics

The analysis included 3,381 young Chinese participants in Singapore, of which 552 had current allergic asthma, as defined by physician diagnosis plus the presence of symptoms in the past 12 months and allergic sensitization to common house dust mites.

Compared with controls who had no allergic asthma, those who did have the medical condition were younger (19.8 vs 22.9 years) and more likely to be male (53.4 percent vs 29.7 percent), have overweight or obesity (17.6 percent vs 15.2 percent), and report nondrinking behaviour (60.3 percent vs 51 percent).

Among participants with current allergic asthma, the condition was mild in 67 percent, moderate in 21.7 percent, and severe in 11.2 percent. Asthma was well controlled in 60.7 percent of participants, partly controlled in 39.3 percent, and poorly controlled in 2.9 percent. Common phenotypes included cough-variant (57.6 percent), wheezy variant (55.1 percent), and exercise-induced variant (31.5 percent), with overlapping symptoms. 

“Our study provides an updated overview of asthma prevalence and phenotype-specific dietary associations in Singapore, emphasizing the potential influence of dietary habits on current asthma severity and exacerbations,” the authors said.

Unlike previous studies on broad dietary patterns such as the Mediterranean diet, the present work looked at specific food groups in relation to prevalent allergic asthma and its phenotypes, they continued. “This approach may be more practical for public health interventions, where food-based guidance is easier for patients to understand than nutrient-based recommendations.”

The authors acknowledged that the associations should be regarded as exploratory given the study’s cross-sectional design and reliance on FFQ-based dietary assessment. Additional studies with larger, independent cohorts using longitudinal designs and a more precise dietary measurement are needed to validate the findings, they said.