 Magnesium and Asthma |
| Contents on this Page: |
Numerous studies show a relationship
between magnesium intake and asthma symptoms and it is suggested that intakes of magnesium
in the general population are deficient.
Extensive metabolic balance studies done by the USDA Research Service showed that the ratio of dietary calcium to magnesium that best maintained equilibrium (i.e., output equaling intake) was 2:1 (Hathaway, 1962).
This ratio is achieved at the median magnesium intake of approximately 600 mg per day. However, dietary surveys taken in the last decade have found that most Americans' diets provide less than 300 mg/day.
Thus, the median daily intake of magnesium in the United States appears to be inadequate.82,83
Magnesium balance has been associated not only with magnesium intake but also with the intake of other nutrients such as fiber, protein, calcium, and phosphorus. Moreover, the effect of these nutrients on magnesium balance varied with age and sex.82
The imbalance between magnesium and calcium has increased because calcium intakes have risen, while magnesium intakes have not.83
Magnesium Deficiency in Bronchial Asthma
The first report of low polymorphonucleur magnesium content in patients with asthma was made in 1995, by P Fantidis and colleagues. They measured the polymorphonuclear magnesium content, and serum and erythrocyte sodium, calcium, and magnesium concentrations in 21 healthy volunteers and 50 patients with different types of asthma.
They found the polymorphonuclear magnesium content was lower than in the control group (P < 0.001), while magnesium levels in erythrocytes and serum and the levels of other ions in erythrocytes and serum were normal.
This is the first report to document low polymorphonuclear magnesium content in patients with bronchial asthma. They concluded that the reduction of polymorphonuclear magnesium content may have an important role in the pathogenesis of asthma.85
A study of hypomagnesemia among 120 ambulatory urban African Americans concluded that the prevalence of magnesium deficiency among this group exceeds that reported in previous studies of the general population. The odds among those having asthma was 4.69 times the rate of the general population. Coincidentally, this corresponds closely with Dr. C. Everett Koop’s note that although African Americans comprise 12% of all asthmatics, African Americans living in an urban setting have a five-fold greater incidence of asthma than the general population, resulting in a death rate three times higher than the death rate of other asthmatics.95
Magnesium in the Treatment of
Asthma
The efficacy of magnesium in the
treatment of bronchial asthma was first reported in 1938 (Haury). Over the past two
decades its brochodilating effect has been reported in patients with mild asthmatic
attacks, and when that was found effective, applied to those with severe attacks.
Animal studies have shown that magnesium deficiency increases the amount of histamine released into the blood.
A study by Britton & Hill indicated that patients with asthma who reported a high dietary intake of magnesium had better lung function and a reduction in the relative risk of wheezing.86
Improvements in FVC, FEV1 and PEF were noted in asthmatic patients receiving magnesium. SP Hauser, et al. reported the effects of intravenously infused Mg-aspartate hydrochloride (MgAHCl) in 17 asthmatic inpatients.
In 11 patients with initial FVC less than or equal to 90%, the median FVC increased after MgAHCl by 56 to 61% (p less than 0.01), the forced expiratory volume at 1 sec. (FEV1) by 40 to 44% (p less than 0.02) and the peak expiratory flow (PEF) by 45 to 56% (p less than 0.02).
The average serum concentration of Mg increased by 0.89 to 1.72 mmol/L and decreased to 1.33 mmol/L 20 minutes after the Mg-infusion.
Intravenous infusion of Mg produces a significant improvement of FVC, FEV1 and PEF.
The researchers concluded that with
its cardioprotective effect and the reduction of bronchial hyperreactivity, Mg could be a
valuable method in the treatment of asthmatic patients.94
Bronchodilating Effect of Magnesium
As reported in the Journal of the American Medical Association, H Okayama, and colleagues, studied the bronchodilating effect of magnesium sulfate (MgSO4) in ten asthmatic patients with mild attacks.
Maximum responses (mean +/- SE) of respiratory resistance, forced vital capacity, and forced expiratory volume were 71% +/- 3%, 117% +/- 5%, and 118% +/- 1% of initial values, respectively, and were similar to the effects of additional albuterol inhalation.
The infusion of MgSO4 also improved dyspnea and piping rales in three other asthmatic patients with a severe attack.
The researchers concluded that intravenous
infusion of MgSO4 produces a rapid and marked bronchodilation in both mild and severe
asthma and may be a unique bronchodilating agent.87
Okayama, et al., reported a second study on magnesium, in 1991, in the Journal of Asthma. They noted the bronchodilating effect of magnesium sulfate (MgSO4) in two patients with status asthmaticus, who were intubated and mechanically ventilated by a respirator.
Airway resistance was continuously monitored by the respiration-controlled interruption technique.
After administration of 0.5 mmol/min MgSO4 intravenously, airway resistance decreased from 17 to 9, (a 47% decrease) and from 13 to 8 mmHg/L/s (a 38% decrease) in the two patients, respectively, and piping rates diminished or disappeared.
They concluded that while
corticosteroid therapy requires several hours to demonstrate significant effects in status
asthmaticus, MgSO4 is of great benefit in the rapid improvement of airflow obstruction.88