Summary of studies
| Study and population (n) | Study Objective | Supplement and dose | Outcome | Quality rating |
|---|---|---|---|---|
| Arm et al, 1988 n=20 | To test the effect of fish oil supplements on asthma control and neutrophil function. | 10 week, daily supplements containing 3200 mg EPA and 2200 mg DHA compared to control group taking olive oil capsules (dose not stated). | 1. No significant difference in self-report symptoms between the two groups. 2. No significant change in neutrophil count. | Strong |
| Arm et al, 1989 n=17 | To evaluate effect of fish oil supplements on airway response to allergens. | 10 week, daily supplement capsules containing 3200 mg EPA and 2200 mg DHA compared to control group taking olive oil (dose not stated). | 1. No significant difference in peak flow, symptom scores or bronchodilator use. 2. Significantly attenuated late asthmatic response following allergen challenge after supplementation. | Moderate |
| Brannan et al, 2015 n=23 | Whether Omega-3 fatty acids inhibit airway sensitivity to inhaled mannitol, a test for bronchial hyper responsiveness. | 3 week, daily dose of 400 mg EPA and 200 mg DHA vs control group taking a placebo containing a blend of omega-6 and omega-9 Fatty acids. | No difference in FEV1 between intervention and control group. | Strong |
| Emelyanov et al, 2002 n=46 | Assess effect of New Zealand Green-lipped mussel supplement on asthma symptoms and Peak expiratory flow rate (PEFR) | 8 week, daily capsule of lipid extract containing 50 mg of polyunsaturated fatty acids EPA and DHA compared to control taking daily 150 mg olive oil capsules. | 1. No difference in mean FEV1 or evening PEFR. 2. Mean morning PEFR higher after supplementation compared to control. 3. Significant reduction in daytime wheeze but not bronchodilator use in intervention group. | Strong |
| Lindermann et al, 2009 n=21 | To evaluate impact of the medical food EFF1009 containing fatty acids gamma-linolenic acid (GLA), DHA and EPA on asthma-related quality of life. | 4 week, daily meal of EFF1009 containing 750 mg GLA, 500 mg EPA, 350 mg DHA compared to control taking a placebo emulsion contained no GLA, EPA, or DHA. | 1. No significant difference in FEV1. 2. Significant improvement in self-reported asthma symptoms using the Asthma Control Questionnaire after supplementation. | Strong |
| Mickleborough et al, 2006 n=16 | To investigate effect of fish oil supplements on exercise induced bronchoconstriction (EIB) | 3 week, daily dose of fish oil capsules containing 3200 mg EPA and 2000 mg DHA compared to control taking olive oil capsules (dose not stated). | 1. No significant difference baseline FEV1. 2. Significant attenuated EIB response after supplements. 3. Significant reduction in bronchodilator use after supplements. | Moderate |
| Mickleborough et al, 2013 n=20, | Evaluate the effect of New-Zealand green-lipped mussel supplement (PCSO-524) on airway inflammation and bronchoconstrictor response to eucapnic voluntary hyperpnoea (EVH). | 3 week, daily dose of PCSO-524 containing 72 mg EPA and 48 mg DHA compared to control group taking daily 150 mg olive oil capsules. | 1. Bronchodilator use significantly reduced whilst taking supplement compared to normal diet or placebo. 2. Significantly improved mean asthma symptom scores. 3. Significantly improved morning and evening peak flow. | Strong |
EPA: Eicosapentaenoic Acid, DHA=Docosahexaenoic acid, FEV1=Forced Expiratory Flow
Quality Rating adapted from the quality assessment tool for quantitative studies published by the effective public health practice project