Turmeric, Curcumin, Asthma, Lung Function
Objective: Over 23 million people are affected by asthma in the United States and 262 million individuals globally. Asthma, if poorly controlled, is associated with significant morbidity as well as increased risk for mortality. Several complex inflammatory pathways and processes are involved leading to an increase in immune cell activation. Curcumin, the active constituent found in turmeric, has been studied in numerous in-vivo and in-vitro studies to generate anti-inflammatory effects in pulmonary diseases. More recently, an increase in clinical data has become available, and since the most recent review assessing the role of curcumin in pulmonary disorders, additional clinical trials have been published. We provide the first meta-analysis evaluating the efficacy of curcumin supplementation in asthma.
Methods: We searched PubMed and Google Scholar for eligible studies up to June 30, 2021, using medical subject headings and keywords for asthma. Any clinical trial design, conducted in humans, assessing the efficacy of curcumin on asthma related symptoms and lung functioning were included. Two authors, using predefined criteria, independently screened, extracted data, and assessed risk of bias from included studies using predefined criteria. Random effects meta-analysis was performed for each outcome, with effect size reported as mean difference (MD) or as a standardized mean difference.
Results: 1,216 studies were screened, 8 included for review (n = 509) and adequate data from 3 trials (n = 203) included for meta-analysis. Most participants were of female sex (52.2%) and the mean age (SD) of participants was 39.23 (14.7) years. The forced expiratory volume in one second (FEV1%) improved with curcumin supplementation (3 studies; pooled MD = 3.70 (1.00, 6.41), p= 0.007, I2=0%) compared to control. Efficacy of curcumin supplementation on asthma symptoms more generally were discordant and safety data was only reported in two trials.
Conclusions: Supplementation with curcumin may provide small improvements in FEV1%, however conclusions are limited by the small number of studies and sample sizes, poor methodological quality, inconsistent reporting of asthma related outcomes and high risk of bias of included studies. Additional, high-quality, human trials are needed to assess the efficacy of curcumin supplementation more robustly in asthma.
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Grow, Tabitha M. and Sadowski, Adam
"Efficacy of Curcumin Supplementation in Asthma: A Systematic Review and Meta-Analysis,"
PSU McNair Scholars Online Journal:
1, Article 3.