In a recent blog entry, I provided evidence that diet may indeed affect lung function and disease, specifically asthma. Another common lung condition is chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. COPD is usually associated with smoking.
Last year, scientists with the Harvard School of Public Health , Harvard Medical School, and Simmons College concluded that “in men, a diet rich in fruits ,vegetables, and fish may reduce the risk of COPD whereas a diet rich in refined grains, cured and red meats, desserts and French fries may increase the risk of COPD.”
The Boston, MA, researchers included academic heavyweights such as Teresa Fung, Walter Willett, and Frank Hu. They studied 42,917 men in the Health Professionals Follow-up Study via detailed periodic questionnaires. The men at baseline had never had asthma or COPD. Onset of COPD between 1986 and 1998 was evaluated by questionnaire and was defined as an “affirmative response to physician-diagnosed chronic bronchitis or emphysema and by the report of a diagnostic test at diagnosis (pulmonary function testing, chest [x-ray] or chest CT scanning).” Participants reported 111 new cases of COPD.
Investigators identified two distinct major dietary patterns at baseline:
- “Prudent” pattern: high intake of vegetables, fruits, fish, poultry and whole grains.
- “Western” pattern: high consumption of cured and red meats, refined grains, desserts and sweets, French fries, eggs and high-fat dairy products.
The prudent dietary pattern was inversely associatied with the risk of newly diagnosed COPD, regardless of smoking status. In other words, the higher an individual’s conformity to the prudent pattern, the lower the risk of new COPD.
On the other hand, the Western pattern was positively associated with the risk of newly diagnosed COPD, again regardless of smoking status.
They did not note any association between either dietary pattern and the risk of developing asthma.
Clearly, there are similarities between the prudent dietary pattern and the traditional Mediterranean diet. The main differences are that the Mediterranean diet includes significant amounts of olive oil, limited red meat and eggs, and judicious amounts of wine. The Mediterranean diet incorporates the prudent pattern. But the Mediterranean diet is not the “prudent dietary pattern” studied at Harvard. Whether the Mediterranean diet would match or supercede the prudent diet in prevention of COPD is a matter of speculation. The smart money would bet in favor of the Mediterranean diet reducing rates of COPD to at least some degree.
In view of a recent study associating improved asthma control with the Mediterranean diet, you gotta wonder if the researchers would have confirmed it, if they had been looking. Are there substances in olive oil, or other aspects of the Mediterranean diet, that improve lung function?
Many people are aware that dietary patterns have an effect on heart disease, overweight and obesity, high blood pressure, diabetes, dementia, cancer, and strokes. We can add chronic lung disease to the list now.
Steve Parker, M.D.
Reference: Varraso, Raphaelle, et al. Prospective study of dietary patterns and chronic obstructive pulmonary disease among US men. Thorax, vol. 62, (2007): 786-791.