To the Editor.
—The article by Dr Salmerón and colleagues1 provides important new information regarding dietary factors associated with the development of NIDDM. The authors in their "Comment" section, suggest the possible inverse association between the intake of magnesium and the development of NIDDM. However, the authors state that, "The high correlation between cereal fiber and magnesium may not permit a clear separation of the independent effect of magnesium from that of cereal fiber intake."We have conducted several studies to directly evaluate the effects of magnesium on insulin sensitivity and the development of NIDDM. Induction of isolated experimental dietary human magnesium deficiency in normal male volunteers led to insulin resistance,2 a major feature of NIDDM. Furthermore, we recently conducted 2 studies in rat models. In 1 study, correction of the reduced magnesium content in a commercially available high-fructose low-magnesium diet completely normalized insulin resistance.3 In addition, a diet high