There’s no special asthma diet. We don’t know of any foods that reduce the airway inflammation of asthma. Beverages that contain caffeine provide a slight amount of bronchodilation for an hour or two, but taking a rescue inhaler is much more effective for the temporary relief of asthma symptoms.
However, a good diet is an important part of your overall asthma treatment plan. Just like regular exercise, a healthy diet is good for everyone. That goes for people with asthma, too. Obesity is associated...
American Academy of Allergy Asthma & Immunology: "What is an Allergy/Asthma Specialist?" American Academy of Family Physicians: "Asthma: Questions to Ask When It Doesn’t Get Better?" Merck Source: "Questions to Ask Your Doctor."