Magnesium and Heart Health

Magnesium is a mineral with many and diverse functions in the body, and it’s especially important for heart health. Among its many roles, magnesium plays a part in protein synthesis, blood sugar control, muscle and nerve function, blood pressure regulation, bone strength, and heart rhythm regulation.

What Are the Signs of Magnesium Deficiency?

Many people don’t get enough magnesium, mostly due to less than optimal eating habits. Without enough magnesium, inflammation can build up in the body, eventually leading to diseases like cancer, diabetes, and heart disease. Osteoporosis can also occur over time.

Extreme magnesium deficiency is rare, but is more likely to occur if you have kidney disease, Crohn’s disease, or thyroid problems, if you take antibiotics, proton-pump inhibitors, or other medications such as for diabetes or cancer, if you are an older adult, or if you abuse alcohol.

Most people are unlikely to experience symptoms of magnesium deficiency, because the kidneys tightly regulate the excretion of it. Meaning if you’re not eating enough of it, your kidneys will stop dumping it into your urine, and recirculate it for use. Your body can also pull it from your bones if needed. This is how osteoporosis can occur over time.

When symptoms of magnesium deficiency do occur, it can present as low appetite, nausea, vomiting, fatigue, numbness and tingling, muscle cramping, seizures, heart arrhythmia, coronary spasms, and calcium or potassium deficiency.

Chronic low magnesium intake has also been associated with a wide range of disease states, including stroke, high blood pressure, asthma, low back pain, osteoarthritis, diabetes and metabolic syndrome, depression, anxiety, migraines, addiction, sleeplessness, kidney disease, Crohn’s disease, and some cancers.

How Much Magnesium Do I Need for Heart Health?

The DRI (Dietary Reference Intake) for magnesium for women over 30 years old is 310 mg per day, and for men over 30 is 420 mg per day. There are many factors that can cause your body to use more of your magnesium stores, including diseases like diabetes, cancer, and heart disease, as well as everyday events like chronic sleeplessness and stress. For this reason, it’s doubly important to make sure you’re consuming many high magnesium foods daily.

How Do I Know If I Overdose on Magnesium?

Remember that it’s important to try to get your nutrients from the foods you eat, rather than supplements. Foods with magnesium also contain many other nutrients, some of which we probably don’t even know about yet! Plus it’s really hard to overdose on a certain nutrient with food. 

On the other hand, magnesium is considered one of the safest supplements to take, because overdosing on it is very rare. People with healthy kidneys simply excrete excess magnesium in their urine. Sometimes diarrhea can occur – laxatives often work by using large doses of magnesium. In extreme cases of intakes over 5,000 mg/day, death has occurred. Other symptoms of toxicity are actually similar to deficiency: nausea, vomiting, lethargy, and irregular heartbeats, but also hypotension (low blood pressure), and cardiac arrest. The risk of magnesium toxicity does increase if you have kidney disease. Be sure to talk to your doctor before beginning magnesium or any supplements, especially if you are on other medications.

What Foods Are Good Sources of Magnesium?

In general, plant foods are higher in magnesium than animal foods. Here is a partial list of foods with high amounts of magnesium. To search for individual foods, see the USDA’s FoodData Central.

• Pumpkin seeds, 1 oz – 168 mg
• Cooked spinach, 1 cup – 157 mg
• Chia seeds, 1 oz – 95 mg
• Roasted almonds, 1 oz – 80 mg
• Roasted cashews, 1 oz – 74 mg
• Soy milk, 1 cup – 61 mg
• Black beans, ½ cup – 60 mg
• Peanut Butter, 2 Tbsp – 49 mg
• Plain yogurt, 1 cup – 42 mg
• Banana, 1 medium – 32 mg
• Atlantic Salmon, 3 oz cooked – 26 mg

The best way to ensure you’re getting enough magnesium for heart health is to eat a variety of whole plant foods every day, with a special focus on the foods on the above list. With a little planning, it’s not so hard to get all you need! If you’re considering a supplement, always talk to your doctor or dietitian about whether you need it, and what kind is the best for you.