Research published this week in the Annals of the American Thoracic Society demonstrates that a diet high in fiber might reduce the chance of developing lung disease - yet another reason to eat healthily.
Lung disease is a major issue in America and the world at large. Chronic obstructive pulmonary disease (COPD) is the third biggest killer on a global scale.
Despite this fact, ways to curtail and minimize risks to the lungs are few and far between.
The only major recommendation to mitigate the chances of COPD is to stop smoking.
A recent study was carried out at the University of Nebraska Medical Center by Corrine Hanson; she and her team poured over data from the National Health and Nutrition Examination Surveys (NHNES) on the hunt for nutritional clues into lung health.
The NHNES was organized and conducted by the Centers for Disease Control and Prevention (CDC) and involves data from 1,921 people aged 40-70.
The participants completed a survey asking questions about diet and lifestyle; each session also involved a physical examination, making the NHNES a unique and incredibly useful data set.
Dietary fiber and health
Eating high-fiber foods, including vegetables, fruits and grains, already has proven health benefits. Fiber can help us maintain a healthy weight by keeping us feeling fuller for longer; fiber regularizes bowel movements, lowers cholesterol and can reduce the risk of diabetes and heart disease.
The Nebraska team wanted to see if a high dietary intake of fiber would also make a positive difference to lung health. To this end, they split the NHNES data by the amount of fiber consumed. The upper quartile consisted of people who ate at least 17.5 g of fiber per day and the lower quartile consumed less than 10.75 g.
The team adjusted for factors including socioeconomic status, smoking, weight, demographic and health factors before beginning the analysis.
Fiber and lung health
Even after the data had been adjusted for the factors listed above, the lungs of the individuals in the high-fiber group fared better than those in the lowest quartile. Of the high fiber consumers, 68.3% had normal lung function compared with 50.1% of the lower quartile; only 14.8% of the high fiber consumers had airway restriction, compared with 29.8% in the lower quartile.
The results infer that sticking to a high-fiber diet will do your lungs a favor.
Of course, these results alone cannot prove cause and effect; additionally, the authors are quick to note that they did not adjust for physical activity, and they could not analyze fiber's impact on lung function over time.
Having said that, their findings add weight to previous investigations. A study using data from the Atherosclerosis Risk in Communities study found that individuals who consumed the most dietary fiber had the highest lung function, compared with those who consumed the least.
Another previous study found a relationship between higher fiber intake and a lower risk of COPD; another still demonstrated that higher fiber consumption was associated with a 40-50% reduction in respiratory-related deaths.
Hanson hopes that, if the findings are further replicated, public health bodies will be able to "target diet and fiber as safe and inexpensive ways of preventing lung disease."
How could fiber benefit the lungs?
If fiber truly is a protector of the lungs, what mechanisms might it use? The authors believe that it might be due, at least in part, to the proven anti-inflammatory properties of dietary fiber.
Inflammation underlies a number of lung diseases, and a reduction in this response might be enough to improve the lung's overall health. C-reactive protein is believed to be important in the inflammation response and does appear to be reduced in people with high-fiber diets.
Another potential mechanism involves fiber's ability to change the makeup of the gut flora. These changes could protect the body from infections and release lung-protective agents, including neutrophils.
Research into lung health and diet will no doubt continue to throw out intriguing and, perhaps, unexpected results. The evidence for fiber and its protective role seems to be mounting. But, either way, eating additional fruits and vegetables can never be a bad thing.
Medical News Today recently covered research showing that diets high in soluble fiber might help prevent weight gain.