A diet with a high intake of fruits and vegetables may have the potential to prevent COPD in ex-smokers and current smokers, new research suggests.

The Swedish prospective cohort study involving over 44,000 men aged between 45 and 79 found that a high consumption of fruit and vegetables (more than five serves a day) was associated with a 40 percent and 34% reduced risk of COPD among current smokers and in ex-smokers respectively, compared to those with a lower intake (less than 2 serves a day).

Each one serving per day increment in total fruit and vegetable consumption decreased the risk of COPD significantly by 8% (95% CI 4% to 11%) in current smokers and by 4% (95% CI 0% to 7%) in ex-smokers, according to the study that followed the cohort for over 13 years.

The researchers did not find an association between fruit and veg consumption and COPD risk in never-smokers.

The findings confirm a “strong impact of cigarette smoking on the development of COPD” and also indicate that a diet rich in fruit and vegetables may have an important role in prevention of COPD, the research team note in their paper published in Thorax.

“Nevertheless, non-smoking and smoking cessation remain the main public health message to prevent development of COPD,” they added.

An accompanying editorial to the study said that given the “high probability of confounding” in observational studies it might be wise to wait for definitive evidence from a randomised controlled trial to confirm causality.

However,  there was nothing to be lost by acting now, the editorialists said.

“We would argue that clinicians should consider the potential benefits of a healthy diet in promoting lung health, and advocate optimising intake of fruits and vegetables in smokers who are unable to stop smoking,” they concluded.