Coffee may help asthma minimally.

More Info: Citing a study in the Cochrane Database of Systematic Reviews caffeine, such as that found in coffee, can produce a small improvement in airway and lung function for a few hours .  Caffeine is very similar to the drug theophylline, which is used to relieve the symptoms of asthma by opening the airways and lungs.  Unfortunately the scope of the research was not to test if caffeine can relieve asthma symptoms, but to discover if  the ingestion of caffeine prior to any lung capacity test could skew the results.

Welsh EJ, Bara A, Barley E, Cates CJ. Caffeine for asthma. Cochrane Database of Systematic Reviews 2010, Issue 1. Art. No.: CD001112. DOI: 10.1002/14651858.CD001112.pub2

How Does Caffeine Affect the Body?

Caffeine affects the body by increasing alertness, reducing fatigue, and inducing better focus and concentration. Most people tolerate 2 to 4 cups daily without detrimental side effects, but heavier consumption can produce nervousness, irritability, rapid pulse, and insomnia. Certain individuals are especially sensitive to caffeine and may experience restlessness and sleep difficulties, even with small amounts. These effects will more likely arise in people who seldom consume caffeine. Men appear to be more sensitive to caffeine than women as well as those medication and seniors. Type 2 diabetics may experience a slight increase in glucose readings.              

What Are the Side Effects of Caffeine?

Side effects of caffeine include nausea, irritability, nervousness, dizziness, anxiety, insomnia and headaches. Allergic reactions to caffeine include rash, itching, hives, swelling in the mouth, lips or face, trouble sleeping and vomiting. Severe reactions to caffeine include diarrhea, tightness in the chest, irregular heartbeat, numbness in the hands or feet, hallucinations, weak pulse, changes in mood, elevation of blood pressure, dehydration, muscle pain, seizure, ringing in the ears, tremors, heartburn and tingling in the hands and/or feet.