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

Indiana University

Status and phase: Completed; Phase 1

Conditions: Asthma

Treatments: Dietary Supplement: Fish Oil; Dietary Supplement: Ascorbic Acid; Dietary Supplement: Ascorbic Acid Placebo; Dietary Supplement: Fish Oil Placebo

Study type: Interventional

Funder types: Other

Identifiers

NCT01057615

0910000751

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 14 patients

Sex: All

Ages: 18 to 40 years old

Volunteers: No Healthy Volunteers

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)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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14 participants in 3 patient groups

Active Fish Oil + Vitamin C Placebo

Experimental group

Description:

Fifteen subjects will take 10 active fish oil capsules per day and 2 vitamin C placebo capsules per day for 3 weeks.

Treatment:

Dietary Supplement: Fish Oil

Dietary Supplement: Ascorbic Acid Placebo

Fish Oil Placebo + Active Vitamin C

Experimental group

Description:

Fifteen subjects will take 10 fish oil placebo capsules per day and 2 active vitamin C capsules per day for 3 weeks.

Treatment:

Dietary Supplement: Fish Oil Placebo

Dietary Supplement: Ascorbic Acid

Active Fish Oil + Active Vitamin C

Experimental group

Description:

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.

Treatment:

Dietary Supplement: Fish Oil

Dietary Supplement: Ascorbic Acid