Magnesium has never been a nutritional superstar, but in recent years, research has confirmed its many crucial roles in the body and uncovered new potential benefits. Notably, it’s involved in energy production, cell growth, blood pressure, bone health and the functioning of the heart, nerves and muscles.
There’s no doubt that magnesium-rich foods are some of the best choices around—but supplements are another matter.
Heart and blood pressure
Insufficient magnesium intake increases cardiovascular risk. Magnesium is essential for the activity of the heart muscle and the nerves that initiate the heartbeat, and it helps regulate blood pressure. An adequate intake helps prevent arrhythmias, reduce cardiac damage from oxidative stress, keep blood vessels healthy, prevent spasms of coronary arteries that can cause angina, and boost HDL (“good”) cholesterol levels.
So it makes sense that many observational studies have found that people with a high dietary intake of magnesium have a lower risk of heart disease and stroke—or that people who live in areas with hard water (which is high in magnesium) have a lower coronary death rate.
But while several clinical trials have found that people with certain heart problems, coronary heart disease or hypertension may benefit from increased magnesium intake (sometimes from food, sometimes from supplements or injections), others have not. Overall, studies on magnesium supplements for heart health or blood pressure control have had inconsistent results.
Magnesium-rich foods are a big part of the anti-hypertension DASH diet. However, foods rich in magnesium are also rich in other heart-healthy nutrients (such as potassium) and fiber, so it’s hard to separate out the effect of this single mineral.
Magnesium is also essential for the body’s use of insulin and the burning of carbohydrates. Observational studies have linked low magnesium levels to increased risk of diabetes and insulin resistance (which often leads to type 2 diabetes), as well as poor blood sugar control in people with the disease. Several small studies of magnesium supplements in people with diabetes have had positive results. Research is continuing.
Working closely with calcium and vitamin D, magnesium helps form and maintain bones and teeth. Researchers have found that people with high magnesium intakes have greater bone density, and that women with osteoporosis tend to have low magnesium levels.