Effect of Fish Oil and Vitamin C on Exercise-Induced Bronchoconstriction and Airway Inflammation in Asthma

Study Overview
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Brief Summary
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Combining fish oil and vitamin C supplementation will provide a greater anti-inflammatory effect against developing exercise-induced bronchoconstriction (EIB) than either nutritional supplement alone.

Detailed Description
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The aim of this study is to extend previous findings that nutritional supplementation or dietary modification can ameliorate exercise-induced bronchoconstriction. It has been shown in separate studies that fish oil and ascorbic acid (vitamin C) individually protect against EIB by improving pulmonary function and reducing airway inflammation. The main aim of this study is to determine the comparative and additive effects of fish oil and ascorbic acid supplementation on EIB and airway inflammation in asthmatic individuals.

Official Title
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Comparative and Additive Effects of Fish Oil and Ascorbic Acid Supplementation on Exercise-Induced Bronchoconstriction and Airway Inflammation in Asthma

Conditions
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Asthma

Intervention / Treatment
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* Dietary Supplement: Fish Oil
* Dietary Supplement: Ascorbic Acid
* Dietary Supplement: Fish Oil Placebo
* Dietary Supplement: Ascorbic Acid Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of asthma, based on medication use as well as history and symptoms as outlined in the NHLBI Guidelines for the Diagnosis and Management of Asthma Diagnosis of EIB, based on ≥10% fall in post-challenge FEV1, a measure of lung function, after dry air eucapnic voluntary hyperventilation (EVH), a simulated exercise challenge Not currently taking asthma maintenance medication or physician approval to discontinue current asthma medication for the duration of the study Not currently taking any fish oil or ascorbic acid supplements above the level recommended for adequate intake (if currently taking supplements, can participate if the subject stops taking the supplements for 2 weeks before starting the study and throughout the study) Agree to limit fish consumption to 1 fish meal per week throughout the study Agree to avoid vitamin C-rich foods throughout the study Exclusion Criteria: Resting FEV1 (the amount of air blown out in the first second of a forced exhalation) <60% of predicted when off medication Pregnancy History of cardiovascular disease, including hyperlipidemia (high cholesterol) and hypertension (high blood pressure) History of bleeding disorders or delayed clotting time History of diabetes History of seizures Allergy to fish oil or ascorbic acid (vitamin C)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active Fish Oil + Vitamin C Placebo<br>Fifteen subjects will take 10 active fish oil capsules per day and 2 vitamin C placebo capsules per day for 3 weeks. | Dietary Supplement: Fish Oil<br>* 10 fish oil (3.2g EPA + 2.0g DHA) capsules per day for 3 weeks<br>Dietary Supplement: Ascorbic Acid Placebo<br>* 2 placebo ascorbic acid (sucrose) capsules per day for 3 weeks<br>* Other names: Table Sugar;|
| Experimental: Fish Oil Placebo + Active Vitamin C<br>Fifteen subjects will take 10 fish oil placebo capsules per day and 2 active vitamin C capsules per day for 3 weeks. | Dietary Supplement: Ascorbic Acid<br>* 2 pharmaceutical grade ascorbic acid (1500mg) capsules per day for 3 weeks<br>* Other names: Vitamin C;Dietary Supplement: Fish Oil Placebo<br>* 10 placebo fish oil (soy bean oil) capsules per day for 3 weeks<br>* Other names: Soy Bean Oil;|
| Experimental: Active Fish Oil + Active Vitamin C<br>Following a 2-week washout period, all subjects from the other two arms (n=30) will take 10 active fish oil capsules per day and 2 active vitamin C capsules per day for 3 weeks. | Dietary Supplement: Fish Oil<br>* 10 fish oil (3.2g EPA + 2.0g DHA) capsules per day for 3 weeks<br>Dietary Supplement: Ascorbic Acid<br>* 2 pharmaceutical grade ascorbic acid (1500mg) capsules per day for 3 weeks<br>* Other names: Vitamin C;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary Function |  | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exhaled nitric oxide to measure airway inflammation |  | 8 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Asthma, Exercise-Induced Bronchoconstriction, Inflammation, Airway, Fish Oil, Ascorbic Acid