The February 2010 issue of the Journal of Asthma published the findings of a clinical trial involving adults with mild to moderate asthma which noted improvements in asthma control and quality of life after six months of supplementation with magnesium.
Alexandra Kazaks, PhD of Bastyr University in Kenmore, Washington, along with colleagues at the University of California, Davis, randomized 55 asthmatic men and women aged 21 to 55 to receive 340 milligrams per day magnesium as magnesium citrate or a placebo for 6.5 months. Bronchial responsiveness, as assessed by a methacholine challenge test, and pulmonary function, assessed by spirometry, were evaluated before and after the treatment period. Questionnaires designed to assess asthma control and quality of life were administered at the beginning and end of the study, and exhaled nitric oxide and serum C-reactive protein were measured to evaluate bronchial and systemic inflammation. Additionally, magnesium in serum, red blood cells and urine, and total body magnesium stores were analyzed. Dietary intake of magnesium was quantified via 24-hour dietary records completed prior to the initial visit and at 3 and 6.5 months.
There were no significant changes in markers of magnesium status or inflammation observed between baseline and end of study values or between the treatment and placebo groups. Nevertheless, bronchial reactivity improved in the group that received magnesium, as indicated by an increase in the concentration of methacholine required to result in a 20 percent decrease in forced expiratory volume. Improvements were also observed in peak expiratory flow rate, and subjective assessments of asthma control and quality of life.
The authors remark that interactions of magnesium with calcium and the influence of the mineral on the cell membrane confer anti-inflammatory and bronchodilatory properties that could help improve asthma control. They suggest that the shorter duration of previous studies that failed to find significant benefits for magnesium in asthma control may not have been sufficient to effect improvements. “Although there is conflicting research regarding magnesium supplementation and asthma outcomes, this study adds to the body of research that shows a beneficial response to magnesium supplementation in people who have mild to moderate asthma,” they conclude.