Molecular hydrogen, particularly inhaled hydrogen gas, may be beneficial in various respiratory conditions, including COVID-19, asthma, and chronic obstructive pulmonary disease (COPD). This may be due to its antioxidant and anti-inflammatory properties as well as its low density, which may improve lung airflow.[1]
In a randomized controlled trial, people experiencing persistent symptoms following a COVID-19 infection reported improved physical function (6-minute walking test) and lung function (forced vital capacity and forced expiratory volume) with inhaled hydrogen gas compared to a placebo. Hydrogen gas (100% hydrogen) was inhaled for 1 hour twice a day for 14 days.[2] In an open-label, multicenter trial in hospitalized patients with COVID-19, inhaled hydrogen gas (66.7% hydrogen and 33.3% oxygen) led to reduced disease severity, reduced chest pain, and a faster improvement in shortness of breath and cough compared to participants receiving oxygen gas alone.[3]
Similar benefits have been observed in people with asthma and COPD. In a multicenter randomized controlled trial, patients with an acute exacerbation (a sudden worsening of disease/symptoms) of COPD saw a greater reduction in symptoms when inhaling hydrogen and oxygen gas over 7 days compared to oxygen alone, but there were no differences in lung function.[4] In a study including people with either asthma or COPD, a single dose of hydrogen gas (2.4% hydrogen inhaled for 45 minutes) led to decreased markers of inflammation in the blood and exhaled breath.[5]
This could represent a novel approach to managing respiratory conditions and is certainly worthy of further research.