Magnesium plays a significant role in hundreds of structural and functional processes in your body. It is especially necessary in the transport of ions that conduct nerve impulses for normal muscle contraction and heart rhythm. Your pulse, or heart rate, is impacted by the amount of magnesium in your body, and deficiency can result in arrhythmias.
Normal Heart Rate
Heart rate is the rate at which your heart pumps blood out to the rest of your body. A normal resting heart rate ranges from 60 to 100 beats per minute. The lower your resting heart rate, the more efficiently your heart functions, and this signifies less work on the part of your heart in getting blood to your organs. A consistently high resting heart rate may indicate underlying abnormalities, including heart disease, magnesium deficiency or medication interactions. Your heart rate normally speeds up during physical activity, stressful events or from smoking and excess caffeine or alcohol. However, in the event of a persistent high resting heart rate, medical intervention may be warranted to prevent a potential heart attack.
Magnesium and Heart Research
Abnormally rapid heart rhythm, or tachycardia, can occur if your magnesium levels are too low. This form of arrhythmia is correctable with magnesium replacement. According to a 1999 report by Dr. Ezra A. Amsterdam, pharmacological doses of magnesium on heart rate and rhythm can reduce the risk of sudden death associated with arrhythmias. Additionally, normal daily intake of magnesium from food sources also may lower your risk of developing abnormalities of heart rate and rhythm. In people with existing congestive heart failure, randomized placebo-controlled studies further reveal that administration of magnesium significantly reduces tachycardia incidence, according to a 1994 study published in "Circulation."
Recommended Daily Allowance
The recommended daily allowance of magnesium for adults is 320 mg for women and 420 mg for men. Food sources of magnesium include hazelnuts, peanuts or almonds, which yields 48 to 78 mg per 1 oz. serving. Bean varieties and whole grains, such as brown rice, bran cereal and oats, provide 63 to 93 mg per 1/2 cup serving. Other foods, such as leafy green vegetables, potatoes and bananas also are a good source of magnesium with 32 to 78 mg per serving.
Tolerable Intake and Precautions
Adverse effects of excess magnesium consumption has not been identified from food sources, but supplemental magnesium exceeding the tolerable upper limit may result in toxicity. The upper intake level from supplements is 350 mg per day. Toxicity may include lethargy, confusion, abnormal cardiac rhythm, muscle weakness and, in severe cases, cardiac arrest. Although some conditions may warrant a higher dose supplement of magnesium, this is generally under the supervision of your medical team. Consult your physician before taking supplemental forms of magnesium.
- Oregon State University Linus Pauling Institute: Magnesium
- MayoClinic.com: Heart Arrhythmias
- MayoClinic.com; Heart Rate: What's Normal?; Edward R. Laskowski, M.D.;2010
- The Magnesium Website; Oral Magnesium for Cardiac Arrhythmias ... ; Ezra A. Amsterdam; 1999
- MedlinePlus: Arrhythmias
- University of Maryland Medical Center: Magnesium