Living in the country may be good for your respiratory health, according to a study conducted in Scotland, which suggests that rural as opposed to urban dwelling is associated with a lower prevalence of Asthma.
Moreover, while the prevalence of COPD (Chronic obstructive pulmonary disease) and emphysema, which are caused primarily by smoking, is similar among country and city dwellers, living in the country appears to be associated with better health status among subjects with these two lung ailments, the study hints.
For their study, Lisa Iversen and colleagues from the University of Aberdeen in the UK analyzed responses to a mailed health questionnaire returned by more than 1,000 adults living in rural areas of Scotland and nearly 1,500 living in urban areas of Scotland.
In analyzing the data, the investigators discovered that the prevalence of “any” lung illness was 28-percent lower among those living in the country compared with those living in cities.
Asthma is an inflammatory disorder of the airways, characterized by periodic attacks of wheezing, shortness of breath, chest tightness, and coughing.
Causes, incidence, and risk factors
Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, the muscles of the bronchial tree become tight and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound. Mucus production is increased.
Most people with asthma have periodic wheezing attacks separated by symptom-free periods. Some asthmatics have chronic shortness of breath with episodes of increased shortness of breath. Other asthmatics may have cough as their predominant symptom. Asthma attacks can last minutes to days, and can become dangerous if the airflow becomes severely restricted.
More information: Asthma
The prevalence of Asthma was 41-percent lower among the rural residents compared with the city dwellers, whereas the prevalence of Eczema/dermatitis was 33-percent lower in the country.
Fewer people living in rural areas reported symptoms indicative of Asthma such as persistent cough and phlegm and breathlessness and wheeze, the investigators report in the medical journal Chest.
Chronic obstructive pulmonary disease (COPD) is a group of lung diseases involving limited airflow and varying degrees of air sac enlargement, airway inflammation, and lung tissue destruction. Emphysema and chronic bronchitis are the most common forms of COPD.
Causes, incidence, and risk factors
The leading cause of COPD is smoking, which can lead to the two most common forms of this disease, emphysema and chronic bronchitis.
Prolonged tobacco use causes lung inflammation and variable degrees of air sac (alveoli) destruction. This leads to inflamed and narrowed airways (chronic bronchitis) or permanently enlarged air sacs of the lung with reduced lung elasticity (emphysema). Between 15% and 20% of long-term smokers will develop COPD.
More information: COPD (Chronic obstructive pulmonary disease)
So why do country dwellers appear to breathe easier? The authors say the current study “prevents us from distinguishing between cause and effect in any relationships found.”
They speculate, however, that there may be differences between rural and urban areas that were not measured in this study such as air pollution, body mass index (BMI), diet, and exposure to farming and other occupational exposures that may account for the observations. Many of these factors are known to be important to long-term lung health.
SOURCE: CHEST, October 2005.
Revision date: July 6, 2011
Last revised: by Janet A. Staessen, MD, PhD