Diet & Nutrition Magnesium Research

Coronary Thrombosis
For the past 15 years evidence has stacked up showing patients with acute coronary thrombosis improve their survival chances by 50-82.5% when given intravenous magnesium of 32-66 mmol in the first 24 hours. The single negative study showing that magnesium had a worsening effect on survival employed a far higher dose of magnesium - 80 mmol - than the other studies (European Heart J, 1991; 12:1215-8), and one other study showing no benefit with magnesium  employed the low dose of 10 mmol in the first 24 hours.

Although it would appear clear to any first-year medical student that magnesium worked well for coronary thrombosis within the optimal dosage level of 30-70 mmol - 10mmol was shown to be too little and 80 mmol was shown to be too much - in 1990/91, the Fourth International Study on Infarct  Survival (ISIS 4) team decided to do a major study which was to definitely determine whether magnesium was beneficial when used for this purpose. although their own meta-analysis of all earlier studies showed that magnesium was beneficial, the ISIS 4  investigators also decided to test magnesium against the drug Catopril and a coronary vasodilator. Astonishingly, the ISIS 4 investigators chose to use the 80 mmol dosage for their study - the one dosage that had been found to be harmful. It should noted that the ISIS 4 study was funded to the tune of £6 million by Bristol-Myers Squibb, the manufacturers of Catopril. Not surprisingly, magnesium lagged behind the drugs.

As a result of this paper many hospitals ceased using magnesium in their treatment of the acute coronary thrombosis.

The scandalous decision to use this overdose of magnesium in this study must have caused the loss of several hundred lives within the study and many other lives in other hospitals that have now stopped using magnesium. Both nutritional pioneer Dr Stephen Davies and Dr Damien Downing, editor of the Journal of Nutritional and Environmental Medicine, criticised the designers of the study for clearly selecting too large a dose of intravenous magnesium, and also for giving magnesium too late and then too quickly. Downing even titled his editorial " Is ISIS 4 research misconduct" (J Nutr Environ Med, 1999; 9: 5-13)

WDDTY, November 1999, Vol 10, No 8