Fruits, vegetables diet counter lung diseases



  • Smokers are prone to an increase in risk of developing chronic obstructive pulmonary disease
  • Smoking has a strong impact on the development of COPD, which diet, rich in fruit and vegetables, can significantly prevent.

Research, published this week in Thorax, finds a link between eating greater quantities of fruits and vegetables and lung health. They found that it lowered the risk of developing the chronic obstructive pulmonary disease in former and current smokers.

Chronic obstructive pulmonary disease (COPD) is a range of conditions characterised by a narrowing of the airways, including emphysema and bronchitis. Occurrences of COPD were registered across the time period; there were 1,918 in total. The rate of COPD in those who ate fewer than two portions of fruits and vegetables per day was 1,166 per 100,000 people in current smokers and 506 per 100,000 in former smokers.

However, for those eating five portions per day, the equivalent numbers were 546 and 255, respectively. This means that individuals eating five daily servings of fruits and vegetables had a 35 per cent reduced risk of developing COPD compared with those eating two or less portions. When the reduction in risk was split into current and former smokers, the percentages were 40 per cent and 34 per cent, respectively.

Each extra serving of fruits and vegetables was associated with a 4 per cent lower risk of COPD in former smokers and an 8 percent lower risk in current smokers.

Compared with individuals who had never smoked and who ate five or more portions of fruits and vegetables, current and former smokers who ate fewer than two daily portions were 13.5 times and six times more likely to develop COPD, respectively.

The authors conclude: “The present findings confirm the strong impact of cigarette smoking on the development of COPD and also indicate that diet rich in fruit and vegetables may have an important role in prevention of COPD.

Nevertheless, nonsmoking and smoking cessation remain the main public health message to prevent development of COPD.”

As part of the analysis, the researchers assessed which particular foodstuffs were most effective at reducing the COPD risk. They found that green leafy vegetables, peppers, apples, and pears had the strongest influence on reducing risk.

However, berries, citrus fruits, bananas, root and cruciferous vegetables, tomatoes, garlic, onions, and green peas did not exert a significant effect.

Because smoking increases oxidative stress and inflammation, both of which are potentially involved in COPD, the antioxidants present in fruits and vegetables might help reduce their negative impact.

Although the study was conducted on a large scale, it still needs replication. An editorial, released in the same publication, written by Dr Raphaelle Varraso and Dr Seif Shaheen, argues that because this study is observational, no firm conclusions can be drawn regarding cause and effect; however, they write:”[I]t could be argued that there is nothing to be lost by acting now. 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, especially in smokers who are unable to stop smoking.”

So, although more research will be needed before conclusions can be definitively drawn, quitting smoking and eating more fruits and vegetables are still the best course of action for overall health.