The use of "Pungent Principles" (a term that generally refers to the active, spicy compounds found in certain herbs and foods—such as allyl isothiocyanate in mustard, gingerols in ginger, and capsaicin in chili peppers) to support the bronchial or respiratory system is primarily justified by traditional use. In various systems of herbal medicine, especially Ayurveda, Traditional Chinese Medicine, and Western herbalism, pungent herbs have been used for centuries to help relieve congestion, stimulate expectoration, and support overall respiratory health. These effects are attributed to the ability of pungent compounds to thin mucus, stimulate circulation, and promote sweating, which are believed to help clear respiratory passages.

There is some scientific evidence supporting mild decongestant and expectorant properties for certain pungent herbs (e.g., ginger and garlic), but most research is preliminary, limited in scale, or focused on isolated compounds rather than the broad category of "Pungent Principles." For example, ginger has demonstrated anti-inflammatory and antitussive effects in animal models, and capsaicin is sometimes used in nasal sprays for rhinitis. However, comprehensive clinical evidence specifically linking pungent principles as a group to direct support of the bronchial system is lacking.

In summary, while traditional practices provide the main justification for using pungent principles to support bronchial health, modern scientific support is limited and does not yet fully confirm these traditional uses.