Magnesium is an essential nutrient that plays a critical role in several processes in your body, including nerve and muscle function. What you may not know is that there's a strong connection between magnesium and heart rate.
Read more: Difference Between Magnesium and Manganese
Magnesium and Heart Rate
According to Medline Plus, magnesium contributes to over 300 different biochemical reactions that take place in your body. Your muscles require this mineral to contract, your nerves need it to pass signals and your immune system needs it to stay healthy. Magnesium also supports bone health, regulates blood glucose levels and helps your body produce energy and proteins.
This mineral plays a crucial role in cardiovascular health as well. The Office of Dietary Supplements (ODS) notes that it helps keep your heartbeat steady and that a magnesium deficiency may cause abnormal heart rhythms and coronary spasms.
In fact, like everything health-related, there is a fine balance to be achieved between multiple factors to keep the body working optimally. According to the American Heart Association (AHA), magnesium works with other minerals like calcium and potassium to keep your heart functioning. Even the slightest imbalance in your intake of any of these minerals can cause irregular heart rhythms, or arrhythmias.
According to the AHA, atrial fibrillation and tachycardia are two types of arrhythmias that can be caused by mineral imbalances, and they can have serious, even fatal, consequences, such as cardiac arrest and stroke.
Atrial fibrillation is a condition where abnormal electrical signals interfere with the heart's normal pumping mechanism, while tachycardia is a condition where your heart beats too fast, at a rate of over 100 beats per minute (BPM). The normal resting heart rate in adults is between 60 to 100 BPM, according to the Mayo Clinic. A lower heart rate is a sign of a more efficient heart and better cardiovascular health.
Recommended Magnesium Intake and Sources
The ODS recommends a magnesium intake of 400 milligrams per day for adult men between the ages of 19 and 30 and 420 milligrams per day for adult men above the age of 30. For women, the recommended amount is 310 milligrams per day between the ages of 19 and 30 and 320 milligrams per day above the age of 30. Pregnant women require an additional 40 milligrams of magnesium per day.
According to the ODS, most Americans consume too little of this mineral. Adolescent females and males above the age of 70 are especially likely to have low intakes of magnesium. However, it's worth noting that these insights are slightly outdated since they're based on 2003-2006 data. The ODS notes that there is no current data available. Previous studies have consistently shown low intakes of this nutrient.
Magnesium is an abundant mineral that's naturally found in many foods, added to many fortified products and available in supplement form as well. It's also an ingredient in certain medicines, such as laxatives, antacids and remedies for heartburn and stomach upset. Certain forms of tap, mineral and bottled water also contain magnesium.
The ODS and Medline Plus list some of the foods that contain magnesium. These include dark green vegetables like spinach and broccoli, fruits and dried fruits like bananas, avocados, dried apricots and raisins and nuts, such as almonds, cashews and peanuts. Legumes like edamame, black beans, soybeans and kidney beans, whole grains like brown rice, millet, oats and wheat and dairy products like milk and yogurt are excellent sources, too.
According to the ODS, your body is able to absorb around 30 to 40 percent of the dietary magnesium you consume, and the excess is secreted in your urine. Older adults and people with gastrointestinal problems, type II diabetes and chronic alcoholism may be at greater risk for magnesium deficiency because they have a limited ability to absorb this nutrient or their bodies may excrete more than normal.
Are Magnesium Supplements Necessary?
According to Harvard Medical School (HMS), you should be able to get enough magnesium from food. However, if you're deficient in this mineral, magnesium supplements may help. There are several different types of magnesium supplements, including magnesium citrate, carbonate, gluconate, chloride and oxide. Your body's ability to absorb supplemental magnesium depends on the type of product, notes the ODS.
Studies have shown that supplementing magnesium can be beneficial to heart health. A study published in the journal Hypertension in July 2016 found that magnesium supplements could help lower blood pressure. Another study, which was published in the Journal of the American Heart Association in May 2019, has found that drinking mildly saline water containing minerals like calcium and magnesium was associated with lower blood pressure.
Despite the fact that magnesium supplements are marketed as super pills that can fix everything, they do have side effects like diarrhea, nausea and cramping. The ODS recommends that you limit your intake from supplements to 350 milligrams of magnesium per day. HMS suggests consulting your healthcare provider and getting your blood tested if you suspect that your magnesium levels may be low.
Read more: Signs and Symptoms of Too Much Magnesium
Supplements to Lower Heart Rate
When it comes to heart health, magnesium, calcium and potassium go hand in hand because magnesium is involved in the active transport process that is used to transfer calcium and potassium ions across cell membranes, which is critical to maintaining a steady heartbeat.
While you may need magnesium supplements to lower heart rate, you may need to check your calcium and potassium levels as well. Your doctor will be able to guide you about whether you require any additional supplements to lower heart rate.
In general, it is recommended that you try to meet your nutritional requirements through your diet. In fact, the National Institutes of Health prescribes a Dietary Approaches to Stop Hypertension (DASH) eating plan for better heart health, which focuses on increasing your calcium, potassium and magnesium intake and lowering your sodium intake.
Read more: The 14 Best Foods for Your Heart
The DASH diet recommends eating plenty of fruits, vegetables and whole grains. Add more fish, poultry, beans, nuts and vegetable oils to your meals and limit your consumption of saturated fats, sweets and sugary drinks.
- Medline Plus: “Magnesium in Diet”
- Office of Dietary Supplements: “Magnesium”
- American Heart Association: “Understand Your Risk For Arrhythmia”
- American Heart Association: “Tachycardia: Fast Heart Rate”
- Mayo Clinic: “What's a Normal Resting Heart Rate?”
- Harvard Medical School: “What You Should Know About Magnesium”
- American Heart Association Journals: “Effects of Magnesium Supplementation on Blood Pressure”
- American Heart Association Journals: “Drinking Water Salinity, Urinary Macro‐Mineral Excretions and Blood Pressure in the Southwest Coastal Population of Bangladesh”
- USDA: “2015–2020 Dietary Guidelines for Americans”
- National Institutes of Health: “DASH Eating Plan”
- "Circulation"; Effect of Acute Magnesium on Arrhythmia; C.A. Sueta; 1994