Chronic obstructive pulmonary disease (COPD) refers to the combination of chronic bronchitis and emphysema, resulting in obstruction of airways. Although chronic bronchitis and emphysema are distinct conditions, smokers and former smokers often have aspects of both. In chronic bronchitis, the linings of the bronchial tubes are inflamed and thickened, leading to a chronic, mucus-producing cough and shortness of breath. In emphysema, the alveoli (tiny air sacs in the lungs) are damaged, also leading to shortness of breath. COPD is generally irreversible and can be fatal.

The common cold and other respiratory infections can aggravate COPD. Avoiding exposure to infections or bolstering resistance with immune-enhancing nutrients and herbs can be valuable.

Chronic bronchitis has been linked to allergies in many reports.^{5 6 7} In a preliminary trial, long-term reduction of some COPD symptoms occurred when people with COPD avoided allergenic foods and (in some cases) were also desensitized to pollen.⁸ People with COPD interested in testing the effects of a food allergy elimination program should talk with a doctor.

Nutritional supplements that may be helpful: N-acetyl cysteine (NAC) helps break down mucus. For that reason, inhaled NAC is used in hospitals to treat bronchitis. NAC may also protect lung tissue through its antioxidant activity.⁹ Oral NAC (200 mg taken twice per day) is also effective, improving symptoms in people with bronchitis in double-blind research.^{10 11} Results may take six months.

Vitamin C has mucus-thinning properties and may be helpful with respiratory conditions. A review of nutrition and lung health reported that people with a higher dietary intake of vitamin C were less likely to be diagnosed with bronchitis.¹² Vitamin C was also shown to be related to greater volume of air expired from the lungs—a sign of healthy lung function. As yet, the effects of supplementing with vitamin C in people with COPD have not been studied.

Antioxidants in general are hypothesized to be important for neutralizing the large amounts of free radicals associated with COPD. However, use of antioxidant supplements (synthetic beta-carotene, 20 mg per day, and vitamin E, 50 IU per day) did not help smokers with COPD in a double-blind trial despite the fact that people who ate higher amounts of these nutrients in their diets appeared to have lower risk.¹³

Many prescription drugs commonly taken by people with COPD have been linked to magnesium deficiency, a potential problem because magnesium is needed for normal lung function.¹⁵ One group of researchers reported that a magnesium deficiency was found in 47% of people with COPD (as determined by muscle biopsy) but was not reflected in blood levels of magnesium.¹⁶ In this study, magnesium deficiency was also linked with increased hospital stays. Thus it appears that many people with COPD may be magnesium deficient, a problem that could worsen their condition; moreover, the deficiency is not easily diagnosed.

Intravenous magnesium has improved breathing capacity in people experiencing an acute exacerbation of COPD.¹⁷ In this double-blind study, the need for hospitalization was also reduced in the magnesium group (28% versus 42% with placebo), but this difference was not statistically significant. Intravenous magnesium is known to be a powerful bronchodilator.¹⁸ The effect of oral magnesium supplementation in people with COPD has yet to be investigated.

L-carnitine has been given to people with chronic lung disease in trials investigating how the body responds to exercise.^{19 20} In these double-blind reports, 2 grams of L-carnitine taken twice daily for two to four weeks led to positive changes in breathing response to exercise.

Researchers have also given coenzyme Q10 (CoQ10) to people with COPD after discovering their blood levels of CoQ10 are lower than those found in healthy people.²¹ In that trial, 90 mg of CoQ10 given for eight weeks led to no change in lung function, though oxygenation of blood improved, as did exercise performance and heart rate. Until more research is done, the importance of supplementing with CoQ10 for people with COPD remains unclear.

Herbs that may be helpful: Mullein is classified in the herbal literature as an expectorant (to promote the discharge of mucus) and demulcent (to soothe and protect mucous membranes) herb. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.²² Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodicyton californica), wild cherry bark, horehound (Marrubium vulgare), gumweed, anise, and eucalyptus. Animal studies have suggested that some of these increase discharge of mucus.²³ However, none of these herbs have been studied for efficacy in humans.

Ephedra sinica (Ma huang) has been used by the Chinese for medicinal purposes for over 5,000 years, including for lung and bronchial constriction, coughing, and shortness of breath. However, this herb has the potential for serious side effects and is best used only with the guidance of a physician.

Other integrative approaches that may be helpful: Negative ions may counteract the allergenic effects of positively charged ions on respiratory tissues and potentially ease symptoms of allergic bronchitis, according to preliminary research.^{24 25}

Information about the effects of a particular supplement or herb on a particular condition has been qualified in terms of the methodology or source of supporting data (for example: clinical, double blind, meta-analysis, or traditional use). For the convenience of the reader, the information in the table listing the supplements for particular conditions is also categorized. The criteria for the categorizations are: "Primary" indicates there are reliable and relatively consistent scientific data showing a health benefit. "Secondary" indicates there are conflicting, insufficient, or only preliminary studies suggesting a health benefit or that the health benefit is minimal. "Other" indicates that an herb is primarily supported by traditional use or that the herb or supplement has little scientific support and/or minimal proven health benefit.

1. Pingleton SK, Harmon GS. Nutritional management in acute respiratory failure. JAMA 1987;257:3094–9.

2. Fiaccadori E, Del Canale S, Coffrini E, et al. Hypercapnic-hypoxemic chronic obstructive pulmonary disease (COPD): influence of severity of COPD on nutritional status. Am J Clin Nutr 1988;48:680–5.

3. Efthimiou J, Mounsey PJ, Bensen DN, et al. Effect of carbohydrate rich versus fat rich loads on gas exchange and walking performance in patients with chronic obstructive lung disease. Thorax 1992;47:451–6.

4. Miedema I, Feskens EJM, Heederik D, et al. Dietary determinants of long-term incidence of chronic nonspecific lung diseases. Am J Epidemiol 1993;138:37–45.

5. Bsucinco L, Businco E. Allergic pathogenesis in chronic bronchitis. Allergol Immunopathol (Madr) 1975;3:1–8.

6. Krawczyk Z. Role of allergy of the immediate type in the pathogenesis of chronic bronchitis in adults. Pneumonol Pol 1976;44:829–36 [in Polish].

7. No author listed. Preliminary study on the relation between allergy and chronic bronchitis. Chin Med J 1976;2:63–8.

8. Rowe AH, Rowe A Jr, Sinclair C. Food allergy: its role in the symptoms of obstructive emphysema and chronic bronchitis. J Asthma Res 1967;5:11–20.

9. Van Schayck CP, Dekhuijzen PNR, Gorgels WJMJ, et al. Are anti-oxidant and anti-inflammatory treatments effective in different subgroups of COPD? A hypothesis. Respir Med 1998;92:1259–64.

10. Boman G, Bäcker U, Larsson S, et al. Oral acetylcysteine reduces exacerbation rate in chronic bronchitis: a report of a trial organized by the Swedish Society for Pulmonary Diseases. Eur J Respir Dis 1983;64:405–15.

11. Multicenter Study Group. Long-term oral acetylcysteine in chronic bronchitis. A double-blind controlled study. Eur J Respir Dis 1980;61:111:93–108.

12. Sridhar MK. Nutrition and lung health. BMJ 1995;310:75–6.

13. Rautalahti M, Virtamo J, Haukka J, et al. The effect of alpha-tocopherol and beta-carotene supplementation on COPD symptoms. Am J Respir Crit Care Med 1997;156:1447–52.

14. Shahar E, Folsom AR, Melnick SL, et al. Dietary n-3 polyunsaturated fatty acids and smoking-related chronic obstructive pulmonary disease. Atherosclerosis Risk in Communities Study Investigators. N Engl J Med 1994;331:228–33.

15. Rolla G, Bucca C, Bugiani M, et al. Hypomagnesemia in chronic obstructive lung disease: effect of therapy. Magnesium Trace Elem 1990;9:132–6.

16. Fiaccadori E, Del Canale S, Coffrini E, et al. Muscle and serum magnesium in pulmonary intensive care unit patients. Crit Care Med 1988;16:751–60.

17. Skorodin MS, Tenholder MF, Yetter B, et al. Magnesium sulfate in exacerbations of chronic obstructive pulmonary disease. Arch Intern Med 1995;155:496–500.

18. Okayama H, Aikawa T, Okayama M, et al. Bronchodilating effect of intravenous magnesium sulfate in bronchial asthma. JAMA 1987;257:1076–8.

19. Dal Negro R, Pomari G, et al. L-carnitine and rehabilitative respiratory physiokinesitherapy: metabolic and ventilatory response in chronic respiratory insufficiency. Int J Clin Pharmacol Ther Toxicol 1986;24:453–6.

20. Dal Negro R, Turco P, Pomari C, De Conti F. Effects of L-carnitine on physical performance in chronic respiratory insufficiency. Int J Clin Pharmacol Ther Toxicol 1988;26:269–72.

21. Fujimoto S, Kurihara N, Hirata K, Takeda T. Effects of coenzyme Q10 administration on pulmonary function and exercise performance in patients with chronic lung diseases. Clin Investig 1993;71(8 Suppl):S162–6.

22. Hoffman D. The Herbal Handbook: A User’s Guide to Medical Herbalism. Rochester VT: Healing Arts Press, 1988, 67.

23. Boyd EM. Expectorants and respiratory tract fluid. Pharmacol Rev 1954;6:521–42 [review].

24. Gualtierotti R, Solimene U, Tonoli D. Ionized air respiratory rehabilitation technics. Minerva Med 1977;68:3383–9.

25. Jones DP, O’Connor SA, Collins JV, et al. Effect of long-term ionized air treatment on patients with bronchial asthma. Thorax 1976;31:428–32.