TABLE 2.
Summary of results for complementary and alternative medicines tested in multiple trials
| Intervention group | Control group | Treatment duration | Outcome | First author [ref.] | Country |
| Magnesium | |||||
| Daily oral magnesium amino chelate 450 mg (27.6 mmol) + oral vitamin C placebo | Daily oral vitamin C placebo + oral magnesium placebo | 16 weeks | Difference (+): none No difference (−): FEV1, FVC, PEFR, symptom control, bronchodilator use |
Fogarty [24] | UK |
| 400 mg oral magnesium supplement daily | Oral placebo daily | 8 weeks | Difference (+): asthma symptom score No difference (−): FEV1, PEFR, bronchodilator use |
Hill [25] | UK |
| Vitamin C | |||||
| Daily oral vitamin C 1 g (5.6 mmol) + oral magnesium placebo | Daily oral vitamin C placebo + oral magnesium placebo | 16 weeks | Difference (+): none No difference (−): FEV1, FVC, PEFR, symptom control, bronchodilator use |
Fogarty [24] | UK |
| 1000 mg oral vitamin C daily + “standard” asthma treatment | Oral placebo daily + “standard” asthma treatment | 4 weeks | Difference (+): none No difference (−): FEV1, FVC, FEV1/FVC |
Nadi [26] | Iran |
| n-3 Polyunsaturated fatty acids | |||||
| Two fish oil capsules (455 mg EPA + 325 mg DHA + 10 mg vitamin E) once daily | Two capsules of amide once daily | 2 weeks | Difference (+): none No difference (−): FEV1, ACQ score |
Moreira [27] | Portugal |
| 10–20 g of perilla seed oil daily (n-3 fatty acids) | 10–20 g of corn oil daily (n-6 fatty acids) | 4 weeks | Difference (+): FVC, FEV1 No difference (−): PEFR |
Okamoto [28] | Japan |
| ASHMI | |||||
| Oral ASHMI 600 mg, 1200 mg or 1800 mg twice daily + “standard asthma treatment” | Oral placebo twice daily + “standard asthma treatment” | 1 week | Kelly-Pieper [29] | USA | |
| Four oral ASHMI capsules 3 times a day + prednisone placebo | Prednisone 20 mg once daily + ASHMI placebo | 4 weeks | Difference (+): FEV1, PEFR No difference (−): Symptom score, use of bronchodilators |
Wen [30] | China |
| Vitamin D | |||||
| Six 2-monthly oral doses 6 mL vigantol oil containing 3 mg (120 000 IU) vitamin D3 | Six 2-monthly oral doses 6 mL vigantol oil containing 6 mL organolpetically identical placebo | 52 weeks | Difference (+): SGRQ score No difference (−): ACT score, FEV1, PEFR, symptom control |
Martineau [31] | UK |
| 2 weeks 0.25 mcg oral calcitrol twice daily then 2 weeks combination with oral prednisolone | 2 weeks organoleptically identical lactose placebo twice daily then 2 weeks combination with oral prednisolone | 10 weeks | No difference (−): ACQ score, change in FEV1 | Nanzer [32] | UK |
| 28 weeks 4000 IU once daily with ciclesonide 320 mcg controller therapy | 28 weeks placebo with ciclesonide 320 mcg controller therapy | 32 weeks | No difference (−): lung function (FEV1, PEFR), asthma control/symptom score | Castro [33] | USA |
ASHMI: anti-asthma herbal medicine intervention; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PEFR: peak expiratory flow rate; ACQ: Asthma Control Questionnaire; SGRQ: St George's Respiratory Questionnaire; ACT: Asthma Control Test; EPA: eicosapentaenoic acid.