Our bodies need magnesium to function properly, but its importance is often overlooked. Several chronic conditions, including inflammatory bowel disease (IBD), put people at higher risk of developing magnesium deficiency (low levels of magnesium in the body). Even mild magnesium deficiency can have a dramatic effect on many chronic diseases, including heart disease. Research shows that correcting magnesium levels can have a beneficial effect on heart disease and other conditions.
Magnesium is a mineral that comes from food. It is an important electrolyte that our cells need (like sodium, potassium, and calcium). Magnesium is involved in more than 80 percent of the known metabolic processes in the human body — the chemical reactions that keep our cells and body alive.
Magnesium is especially important for heart muscles, skeletal muscles (such as arm and leg muscles), and the nervous system. Without magnesium, these organs cannot function properly.
Magnesium is absorbed in the intestines (mostly the small intestine), and the kidneys remove excess magnesium. Conditions that affect the gastrointestinal tract (like IBD) or the kidneys (diabetes mellitus) can prevent the absorption of magnesium and lower magnesium levels.
Certain medications can also reduce magnesium levels in the body, including hydrochlorothiazide and furosemide (Lasix), which are diuretics (water pills) commonly used to treat high blood pressure.
Magnesium deficiency can cause a wide variety of symptoms and result in potentially dangerous complications. Magnesium deficiency is also linked to several chronic conditions, including:
Inadequate magnesium levels can cause many problems. Replacing deficient magnesium may improve conditions such as heart disease and diabetes, as well as symptoms of magnesium deficiency.
The symptoms of magnesium deficiency can include:
People at greater risk of low magnesium levels include those with Crohn’s disease, celiac disease, type 2 diabetes, and chronic alcoholism. Older adults, people who take diuretic medications, and those who’ve undergone bowel resection (surgical removal of the intestine) are also at risk.
Magnesium is an electrolyte — a mineral that is important for normal electrical activity in the heart, muscles, and nerves. In addition to its role as an electrolyte, magnesium is necessary for most of the chemical reactions that occur inside the body’s cells.
Low magnesium levels have been found to contribute to diseases of the heart and arteries, including:
Research has shown that a higher magnesium intake is associated with a decreased risk of:
However, some of these studies are based on people eating healthier diets in general, which may decrease the risk of these medical conditions regardless of their magnesium content.
Researchers have also found that low magnesium levels are associated with an increased risk of death from coronary heart disease and sudden cardiac death. However, one research study in women found that lower magnesium levels were not associated with an increase in coronary heart disease. Higher magnesium levels were still associated with fewer deaths due to heart disease.
Although the effects of low magnesium levels on the cardiovascular system are clear, research into how correcting magnesium levels can improve these conditions has provided some mixed results. Some research has shown that increased magnesium intake from food can reduce the risk of stroke, heart failure, diabetes, and death due to other causes (all-cause mortality). However, this increased magnesium intake was not associated with a reduced risk of coronary heart disease or cardiovascular disease.
Meanwhile, meta-analyses — which are not as strong scientifically as systematic analyses — indicate that magnesium intake does not affect mortality (death rate) caused by cardiovascular disease.
Elevated magnesium levels may also be dangerous. Magnesium levels may be high in people with acute or chronic kidney disease, malnourishment, certain endocrine disorders, alcoholism, and in some people who use long-term medications that contain magnesium such as some antacids. When magnesium levels are too high, they may be associated with low blood pressure (hypotension), confusion, and sudden death.
Measuring magnesium levels in the body is not always easy. Less than 1 percent of magnesium in the body is found in the blood. Most of it is stored in body tissue, including muscle and bone. Blood levels of magnesium (also called serum magnesium levels) do not always reveal magnesium deficiency.
Because healthy kidneys tightly control magnesium levels in the blood, other tests may be needed to find magnesium deficiency, such as a 24-hour urine test after an injection of magnesium. Blood tests for other electrolytes, including calcium and potassium, as well as standard blood tests for kidney function are also helpful for diagnosing low magnesium levels.
Research suggests that many people do not get enough magnesium from their diet. Over time, eating a diet low in magnesium can cause low magnesium levels in the body at baseline. Conditions like IBD, which can cause inflammation and poor nutrient absorption along with chronic diarrhea, are also likely to lead to low magnesium levels.
Talk to your doctor or other health care provider if you are concerned about your magnesium levels. Make sure you discuss your diet, digestive symptoms, medications, and any other medical conditions so that your doctor has all the information they need to assess your magnesium status.
Although the effects of magnesium intake on heart disease are unclear, some studies suggest magnesium could play an important role in reducing risk factors for heart disease, including diabetes and high blood pressure.
Unless you’re living with kidney failure or other conditions that can cause dangerously high levels of magnesium, increasing magnesium intake may be beneficial to your health.
Magnesium levels can be increased by eating more magnesium-rich foods or by using oral magnesium supplements. Food can be a better source of magnesium than supplements, at least in people who can absorb enough magnesium in their digestive tract.
Research suggests that increasing dietary magnesium intake may lower the risk of death from cancer and other causes.
Fortunately, there are many different types of food sources of magnesium, including:
Oral magnesium supplements can be useful for correcting magnesium deficiency and may be helpful if you have a condition that causes poor magnesium absorption (such as IBD) or increased magnesium excretion (such as kidney dysfunction or diabetes). There are many chemical forms of magnesium.
Some supplements are absorbed better than others, and some are more likely to cause undesirable side effects, such as diarrhea. Research indicates that dietary supplements with magnesium lactate and magnesium chloride are better absorbed than other forms, with less risk of causing diarrhea.
Magnesium citrate (used as a laxative) and magnesium gluconate can be well-absorbed by the body but at the risk of causing diarrhea.
Although some research has indicated that magnesium supplements may be associated with lower cardiovascular disease, the evidence is far from conclusive. Systematic reviews have shown magnesium supplementation provides either inconsistent or no benefit to cardiovascular health.
Moreover, magnesium supplements carry a risk of providing too much magnesium, which, at dangerously high levels, can cause:
Having kidney failure can contribute to high magnesium levels from supplements or diet if the kidneys cannot remove excess magnesium from the body. Additionally, magnesium supplements can interfere with certain medications.
Due to the inconsistent positive health effects of magnesium supplementation, along with the potential health risks, researchers are hesitant to establish a firm recommendation for routine supplementation.
Proper nutrition is a cornerstone of a healthy body. Magnesium, other minerals, and vitamins are all essential to good health, but it is too early to draw conclusions about the role of magnesium in heart disease.
A healthy and diverse diet is the best way to get the nutrients your body needs. If you are concerned about magnesium deficiencies or would like to know how increasing your magnesium levels may affect your heart health, follow up with your health care provider.
Too much magnesium intake can lead to negative outcomes, so be sure to talk to your doctor before starting magnesium supplements.
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