Principal Proposed Treatments

Aromatic essential oils, such as eucalyptus oil and peppermint oil (menthol), have a long history of use as inhalation treatments for respiratory infections. Because the supporting evidence for such treatments is quite weak, they are discussed below in Other Proposed Treatments. Considerably better evidence supports the use of certain essential oils when taken by mouth.

One combination of essential oils has been extensively evaluated as a treatment for respiratory problems. This mixture, called essential oil monoterpenes, consists of cineole from eucalyptus, d-limonene from citrus fruit, and alpha-pinene from pine. Numerous double-blind, placebo-controlled trials, many of substantial size, indicate that essential oil monoterpenes can aid recovery from sinusitis, bronchitis, and other respiratory conditions.^1-7

One large study evaluated the effectiveness of essential oil monoterpenes for acute bronchitis. In this 2-week, double-blind, placebo-controlled trial of 676 people with acute bronchitis, participants received either placebo, essential oil monoterpenes, or one of two antibiotics.⁵ The results indicate that the essential oil mixture was significantly more effective than placebo and at least as effective as antibiotic therapy.

For more information, including dosage and safety issues, see the full Essential Oil Monoterpene article.

An alcohol extract made from the herb Pelargonium sidoides has become popular in Germany as a treatment for various respiratory problems. In one double-blind, placebo-controlled study, 468 adults with recent onset of acute bronchitis were given either placebo or a standard alcohol extract of Pelargonium sidoides 3 times daily for a week.¹³ The results showed a significantly greater improvement in symptoms in the treatment group as compared to the placebo group. On average, participants who received the real treatment were able to return to work 2 days earlier than those given placebo. Benefits were also seen in two other studies enrolling a total of about 350 people.^14-15 When researchers pooled the results of 4 well-designed, placebo-controlled trials, they found that a standardized extract of Pelargonium performed significantly better than placebo at reducing the symptoms of bronchitis by the seventh day of treatment.¹⁸

For more information, including dosage and safety issues, see the full Pelargonium sidoides article.

Other Proposed Treatments for Acute Bronchitis

A large (361-participant) double-blind, placebo-controlled study found evidence that use of a standardized combination of thyme and primrose root extract enhanced recovery from acute bronchitis.¹⁷ Symptoms improved rapidly in both groups, but improvement was faster and the response rates were higher for the thyme-primrose combination compared to placebo.

One double-blind, placebo-controlled study found that use of 200 mg per day of vitamin C enhanced recovery among 57 elderly patients hospitalized for respiratory conditions.⁸ Researchers have also studied the possible role of vitamin A in preventing and treating respiratory tract infections. A review of 10 trials involving over 33,000 children under age 7 years found that, in the majority of cases, vitamin A did not reduce the incidence of infection or symptoms in young children.¹⁹ In two of the studies, vitamin A was beneficial for undernourished children. However, children with adequate nutrition actually faired worse.

As mentioned above, inhaled essential oils have a long, traditional use for respiratory infections. However, while there is some preliminary scientific support for such treatments,^9-12 it is still far too weak to rely upon.

One study provides weak evidence that a standardized combination of horseradish and nasturtium might be helpful for the treatment of bronchitis in children.¹⁶

Numerous herbs have a reputation for helping bronchitis. These include: elecampane, horehound, licorice, marshmallow, mullein, slippery elm, and yerba santa.

It is widely believed by many proponents of alternative medicine that cow’s milk and related dairy products increase mucus in the lungs and sinuses, and should therefore be avoided by people with bronchitis problems. However, there has not been sufficient scientific investigation into this belief to either confirm or deny it.

Because acute bronchitis tends to develop during the course of a common cold, all of the natural treatments used to prevent or treat colds are worth considering. See the Common Cold article for detailed information on these options. In addition, because bronchitis is often a form of temporary asthma, the treatments discussed in the Asthma article are worth considering, as well.