Effect of Increased Fruit and Vegetable Intake on Chronic Obstructive Pulmonary Disease (COPD)

Not Applicable

Completed

Conditions: Chronic Obstructive Pulmonary Disease

Interventions: Behavioral: 5 portions fruit and vegetables/day

Registration Number: NCT00435708

Lead Sponsor: Queen's University, Belfast

Brief Summary: Chronic obstructive pulmonary disease (COPD) is the UK's fastest growing fatal disease and is estimated to cost the health service close to £1 billion every year. Around 80,000 people in Northern Ireland suffer from COPD. COPD is clinically defined as a slowly progressive condition characterised by airflow limitation, which is largely irreversible. Chronic inflammation and oxidative stress are key components of the underlying pathological process resulting in airflow limitation. Dietary factors and nutrients that have antioxidant or anti-inflammatory properties are therefore of interest with respect to the aetiology of COPD. The antioxidant vitamins C, E and beta-carotene are all present in the lung milieu. Such antioxidants represent the lung's first line of defence against oxygen free radicals. Observational studies indicate that a low dietary intake of antioxidant nutrients, or foods rich in antioxidants (e.g. fruit and vegetables), is associated with decreased lung function and increased risk of COPD. To date, there have been no food-based dietary interventions investigating the effect of increased fruit and vegetable intake on COPD. The investigators propose to recruit people with mild to moderate COPD and low fruit and vegetable intakes (\<=2 portions daily) and randomise them to one of two study arms for 12 weeks - either to increase fruit and vegetable consumption to at least 5 portions a day, or to follow their normal diet. Airway and systemic oxidative stress and inflammation will be assessed at baseline and post-intervention in order to determine if fruit and vegetables have the potential to alleviate the oxidative stress and airway inflammation associated with COPD.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 81

Inclusion Criteria

moderate to severe COPD (according to GOLD classification)
oxygen saturation >= 92 KPa
symptomatically stable
habitually low fruit and vegetable intakes (<=2 portions daily)
exercise limited by shortness of breath (rather than e.g. angina, arthritis)

Exclusion Criteria

diabetes
taking antioxidant supplements or drugs
oxygen saturation <8KPa

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
High fruit and vegetables	5 portions fruit and vegetables/day	5 portions fruit and vegetables/day

Primary Outcome Measures

Name	Time	Method
Self-reported Intake of Fruit and Vegetables (Number of Portions Per Day);	12 weeks	A series of 7-day diet histories were completed by each participant at weeks 0 and 12 in order to assess baseline diet and self-reported compliance with the intervention; average daily FV intake was then hand-counted from these records;
Markers of Airway Inflammation in Induced Sputum - Sputum 8-isoprostane	12 Weeks	Markers of Airway Inflammation in Induced Sputum - Sputum 8-isoprostane ng/ml

Secondary Outcome Measures