An area that has receive only a little scientific interest and virtually none from the news media is the connection between diet and respiratory health. A study of over 2,000 children aged 11-19 in southern California was done to examine this issue. The study appeared in the January 15, 2002 edition of the American Journal of Epidemiology.
Low magnesium and potassium intakes were associated with lower lung function. The effect was stronger for magnesium than for potassium. Reductions in lung function were larger in children with asthma.
Magnesium is found in green leafy vegetables, nuts, whole grains, milk, and meats. Highly
refined grains have very little magnesium. Many children eat diets heavy on those foods and so have inadequate intake of magnesium. The adverse effects were seen primarily in the group in the lowest 20 percent of mineral intake. While low intake was bad, excess intake
will not improve lung function.