More than 300 different biochemical processes in the body require magnesium. This essential mineral plays roles in maintaining cardiac function, muscle and nerve action, the immune system and bone health. Although only a small fraction of the body's magnesium is found in the blood, it is important for blood pressure regulation.
Amounts
The National Institutes of Health reports that magnesium requirements depend on age and sex. Adult men ages 19 to 30 require 400 milligrams of magnesium per day and women need 310 milligrams per day. Men over the age of 31 need 420 milligrams and women in the same age group need 320 milligrams daily. Children should receive 80 milligrams per day between the ages of 1 and 3, 130 milligrams per day between ages 4 and 8 and 240 milligrams between ages 9 and 13. Teen boys ages 14 to 18 need 410 milligrams per day while teen girls require 360 milligrams. Older adults and African-Americans have higher rates of magnesium deficiency that the general population.
Hypertension
Magnesium-rich foods are usually also high in potassium and fiber, making it difficult to assess the effect of magnesium alone. However the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure has reviewed clinical trial data and recommends a diet high in magnesium for people with hypertension. Individuals with pre-hypertension can also benefit from a diet high in magnesium, potassium and fiber.
Other Cardiovascular Benefits
A 2009 study in the Journal of the American Academy of Nurse Practitioners examined existing randomized control trials to determine whether there was a link between magnesium and heart disease. They found that higher dietary magnesium intake was associated with a small reduction in the risk of heart disease in male subjects. A subsequent study in the American Journal of Clinical Nutrition reported that high plasma levels of magnesium reduced the risk of sudden cardiac death in women.
Sources
Green leafy vegetables are excellent sources of magnesium. Some legumes, nuts and seeds are also high in magnesium, including almonds, cashews, lentils and soybeans. Whole, unrefined grains in cereals and bread are good sources of magnesium. Supplements are also available. As with any new vitamin supplement, consult your doctor before taking magnesium to determine whether it is right for you.
References
- National Institutes of Health: Dietary Supplement Fact Sheet: Magnesium
- American Journal of Clinical Nutrition: Plasma and dietary magnesium and risk of sudden cardiac death in women
- Journal of the American Academy of Nurse Practitioners: Oral magnesium supplementation in adults with coronary heart disease or coronary heart disease risk
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