Yet 70 to 80% of the US population does not meet the recommended intake of 400 mg per day of magnesium. A recent study reported that the average magnesium intake was 326 mg per day for Caucasian men, 237 mg per day for African-American men, and 297 mg per day for Mexican-American men. The corresponding numbers for women in these ethnic groups were 237, 177, and 221 mg per day, respectively (Ford and Mokdad, J. Nutr., 133: 2878-2882, 2003).
So most of us are getting between 74 mg and 223 mg less magnesium every day than we should be. That's not good, but it's not terrible either. Does that daily magnesium deficit make a difference? Should we be trying to do something about it?
Two small clinical studies suggested that magnesium might affect heart health. The investigators restricted dietary magnesium intake in healthy postmenopausal women to 101 - 130 mg per day. Those studies showed that low magnesium intake caused irregular heartbeats in otherwise healthy women and that this could be reversed by simply supplementing with RDA levels of magnesium.
Because of these and other studies suggesting that low magnesium intake may increase the risk of cardiovascular disease, scientists at Harvard decided to do a meta-analysis of as many high quality studies as they could identify that correlated either blood levels of magnesium or dietary intake of magnesium with heart disease risk (Del Gobbo et al, Am. J. Clin.
Nutr., 98: 160-173, 2013).
They identified 16 high quality studies with 313,041 subjects for inclusion in their analysis. Their analysis clearly showed the importance of magnesium in reducing heart disease risk. There was a 30% decrease in overall heart disease prevalence for every 0.2 mmol/L increase in blood magnesium levels.
Perhaps more to the point, there was a 22% decreased heart attack risk for every 200 mg per day increase in dietary magnesium intake. That's significant because most of us are getting 100 - 200 mg per day less magnesium in our diet that we should be.
The Bottom Line
So what is the bottom line for you?
- If you're like most Americans, you're probably not getting enough magnesium in your diet on a daily basis. In fact, you're probably getting somewhere between 74 mg per day and 225 mg per day less than you should be. That matters because a deficit of as little as 100 to 200 mg per day can increase your risk of heart attack by 11% to 22%.
- You don't need megadoses of magnesium. You can make up some of that 74 to 225 mg per day deficit by increasing your intake of magnesium rich foods like whole grains, nuts, seeds, and many vegetables.
- If you are using a multivitamin or calcium supplement to ensure your intake of essential nutrients, look for ones that provide 200 to 400 mg of magnesium.
To Your Health!
Dr. Stephen G Chaney
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.