Discussion: Glutathione - Essential antioxidant at the cellular level. (Relevant for COPD patients as well)

Regular consumption of natural foods rich in sulfur may strengthen the damaged immune system of COPD patients.

Glutathione is of enormous importance in the proper functioning of the immune system. Prolonged glutathione deficiency can cause severe illnesses, including cancer. Glutathione cannot be consumed in its active form; the liver must synthesize its active form. (There are glutathione injections on the market, but their effectiveness is unclear.) Eating sulfur-rich foods such as avocado, cabbage, cauliflower, kale, broccoli, onion, and garlic significantly improves the body's glutathione level.

Link: Comprehensive Detoxification Guidelines.
https://www.sf-healing.com/page/113 (Copy & Paste)