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