The ketone diet has been shown, in a recent scientific study, to supress NLRP3 inflammasone which is a major driver of COPD and other chronic diseases.

https://www.ncbi.nlm.nih.gov/m/pubmed/25686106/

It suggest that diet might be important when it comes to the management of COPD. A ketone diet is essentially a diet low in acellular (man-made) carbohydrates and sugar. Ketone bodies are produced when the body starts breaking down fat for energy. You need to reduce your glucose and insulin levels before the body will start metabolising fat.

Fasting, high-intensity exercise and avoiding sugar or carbohydrates in your diet has been shown to raise ketone bodies. The link below will take you to a great article on the ketogenic diet.

https://www.inverse.com/article/40558-keto-diet-body-reset-science