Chronic bronchitis has been linked to allergies in many reports.^{3 , 4 , 5} 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.⁶ People with COPD interested in testing the effects of a food allergy elimination program should talk with a doctor.

NAC (N-acetyl cysteine) 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.⁷ Oral NAC, 200 mg taken three times per day, is also effective and improved symptoms in people with bronchitis in double-blind research.^{8 , 9} However, NAC was ineffective in one study.¹⁰ Results may take six months. NAC does not appear to be effective for people with COPD who are taking inhaled steroid medications.¹¹

In a double-blind study, people with COPD received creatine or a placebo for 12 weeks. After the first 2 weeks of supplementation, all participants underwent an outpatient pulmonary rehabilitation program. Compared with the placebo, creatine significantly increased muscle strength, muscle endurance, and overall health status, but not exercise capacity.¹² The amount of creatine used in this study was 5 grams three times a day for 2 weeks, and then 5 grams once a day for 10 weeks.

One double-blind trial found an ivy leaf extract to be as effective as the mucus-dissolving drug ambroxol for treating chronic bronchitis.¹³

L-carnitine has been given to people with chronic lung disease in trials investigating how the body responds to exercise.^{14 , 15} In these double-blind trials, 2 grams of L-carnitine, taken twice daily for two to four weeks, led to positive changes in breathing response to exercise.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.¹⁶ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.¹⁷ However, none have been studied for efficacy in humans.

Researchers have also given coenzyme Q10 (CoQ10) to people with COPD after discovering their blood levels of CoQ10 were lower than those found in healthy people.¹⁸ In that trial, 90 mg of CoQ10 per day, 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.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.¹⁹ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.²⁰ However, none have been studied for efficacy in humans.

Caution: Do not use eucalyptus oil internally without supervision by a healthcare professional. As little as 3.5 ml of the oil taken internally has proven fatal.

Herbs commonly used as expectorants in traditional medicine include eucalyptus, elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), and anise(Pimpinella anisum). Animal studies have suggested that some of these herbs increase discharge of mucus.²¹ However, none have been studied for efficacy in humans.

A greater intake of the omega-3 fatty acids found in fish oils has been linked to reduced risk of COPD,²² though research has yet to investigate whether fish oil supplements would help people with COPD. In a double-blind trial, people with COPD received a fatty acid supplement (providing daily 760 mg of GLA [gamma-linolenic acid], 1,200 mg of ALA [alpha-linolenic acid], 700 mg of EPA [eicosapentaenoic acid], and 340 mg of DHA [docosahexaenoic acid]) or a placebo (80% palm oil and 20% sunflower oil) during an eight-week rehabilitation program. Compared with the placebo, the fatty acid supplement significantly improved exercise capacity.²³ While two of the fatty acids supplied in this supplement (EPA and DHA acid) are found in fish oil, it is not known which components of the supplement were most responsible for the improvement. Gamma-linolenic acid is found in evening primrose oil, black currant seed oil, and borage oil; alpha-linolenic acid is found in flaxseed oil and other oils.

A greater intake of the omega-3 fatty acids found in fish oils has been linked to reduced risk of COPD,²⁴ though research has yet to investigate whether fish oil supplements would help people with COPD. In a double-blind trial, people with COPD received a fatty acid supplement (providing daily 760 mg of gamma-linolenic acid, 1,200 mg of alpha-linolenic acid, 700 mg of eicosapentaenoic acid, and 340 mg of docosahexaenoic acid) or a placebo (80% palm oil and 20% sunflower oil) during an eight-week rehabilitation program. Compared with the placebo, the fatty acid supplement significantly improved exercise capacity.²⁵ While two of the fatty acids supplied in this supplement (eicosapentaenoic acid [EPA] and docosahexaenoic [DHA] acid) are found in fish oil, is not known which components of the supplement were most responsible for the improvement. Gamma-linolenic acid is found in evening primrose oil, black currant seed oil, and borage oil; alpha-linolenic acid is found in flaxseed oil and other oils.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.²⁶ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.²⁷ However, none have been studied for efficacy in humans.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.²⁸ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.²⁹ However, none have been studied for efficacy in humans.

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.³⁰ One group of researchers reported that 47% of people with COPD had a magnesium deficiency.³¹ In this study, magnesium deficiency was also linked to increased hospital stays. Thus, it appears that many people with COPD may be magnesium deficient, a problem that might worsen their condition; moreover, the deficiency is not easily diagnosed.

Intravenous magnesium has improved breathing capacity in people experiencing an acute exacerbation of COPD.³² In this double-blind study, the need for hospitalization also was 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.³³ The effect of oral magnesium supplementation in people with COPD has yet to be investigated.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.³⁴ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.³⁵ However, none have been studied for efficacy in humans.

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.³⁶ As yet, the effects of supplementing with vitamin C in people with COPD have not been studied.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.³⁷ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.³⁸ However, none have been studied for efficacy in humans.

Mullein is classified in the herbal literature as both an expectorant, to promote the discharge of mucus, and a demulcent, to soothe and protect mucous membranes. Historically, mullein has been used as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion.³⁹ Other herbs commonly used as expectorants in traditional medicine include elecampane, lobelia, yerba santa (Eriodictyon californicum), wild cherry bark, gumweed (Grindelia robusta), anise(Pimpinella anisum), and eucalyptus. Animal studies have suggested that some of these herbs increase discharge of mucus.⁴⁰ However, none have been studied for efficacy in humans.