Curcumin improves step 4 asthma treatment: placebo-controlled, single blind study

Background: Despite multistep efforts, many asthma patients remain symptomatic. Anti-inflammatory activities of curcumin are shown. Aim of the study was to analyse the impact of curcumin add-on therapy on inflammatory parameters, lung function, disease control and quality of life in asthma patients. Subjects and methods: Three-months lasting study was done on 150 non-smokers with asthma, that were treated with stable, moderate dose of inhaled glucocorticoids (IGK) and divided into three groups (n=50 each): curcumin group (receiving curcumin 500 mg per os twice daily), placebo group (receiving placebo tablets) and control (non-intervention) group. Sputum eosinophils (sEo), blood eosinophils (bEo), high sensitive C-reactive protein (hsCRP), predicted forced expiratory volume in first second (FEV1%), Asthma Control Test (ACT) and mini Asthma Quality of Life Questionnaire (mAQLQ) were compared before and after study, as well as between groups. Results: Before study, all followed parameters were similar between groups. After study, FEV1%, ACT and AQLQ were improved in all groups, but these improvements were more prominent in curcumin group than in placebo and control. Additionally curcumin group only showed improvement in sEo, bEo and hsCRP. Furthermore, curcumin group showed more frequent clinically significant improvement in ACT score (change>3) and in mAQLQ score (change≥0.5) when compared to placebo and control. On the other side, after study FEV1%, ACT, mAQLQ, hsCRP, sEo and bEo were similarly distributed among placebo and control group. Conclusion: This is the first placebo controlled and single-blind study to suggest that add-on therapy with curcumin could improve lung function, disease control and quality of life in moderate partially controlled asthma. Future studies may benefit from a larger sample size, longer study duration, double blind design, different dose of curcumin and/or improvements in oral bioavailability.