Q. Years ago, I read that a cough associated with asthma could be relieved by taking cough lozenges with vitamin C. I tried it and it works. It has been almost six years and now I only cough when I run out. I use one or two a day. I wish I had such an easy way to get the wheezing under control when it acts up.
A. A systematic review of three studies of vitamin C in people with asthma found that vitamin C may reduce the likelihood of an asthma attack after a cold (Allergy, Asthma and Clinical Immunology, Nov. 26, 2013). The doses in the studies were between 1 and 5 grams daily.
Ascorbic Acid against Asthma from Exercise
Research suggests vitamin C may benefit people with asthma when they are exercising or have a respiratory infection (Journal of Allergy and Clinical Immunology, online Sept. 26, 2014). A recent methodical review of the relevant research on vitamins C and E for asthma and exercise-induced wheezing concluded that there are not enough strong studies to come to a conclusion on the helpfulness of these supplements one way or the other (Cochrane Database of Systematic Reviews, June 17, 2014).
Curcumin for Wheezing
Much of the research on supplements to reduce wheezing due to asthma has been conducted in children. We found one intriguing but preliminary study hinting that curcumin supplements (500 mg twice daily for a month) in addition to standard asthma medication could ease airway obstruction and reduce wheezing (Journal of Clinical and Diagnostic Research, online Aug. 20, 2014).
Our usual caution is that curcumin (the active compound in the spice turmeric used to make curry powder tasty and yellow) can interact with the anticoagulant warfarin. Although this has not been definitively established in a study, several readers have reported bleeding problems or elevated INR levels on the combination, so we recommend against taking both.