High blood pressure, also known as hypertension, is a serious health condition that increases the risk of heart disease, stroke, and other health problems. An estimated 1 in 3 American adults has high blood pressure, which is defined as a systolic blood pressure (top number) of 130 mmHg or higher or a diastolic blood pressure (bottom number) of 80 mmHg or higher. While there are medications that can help lower high blood pressure, lifestyle changes like following a healthy diet, exercising regularly, avoiding tobacco, and reducing stress are also important. Some research suggests that getting enough magnesium may help lower high blood pressure too.
What is magnesium and what does it do in the body?
Magnesium is an essential mineral that plays many important roles in the body. It helps regulate blood pressure, blood sugar levels, and muscle and nerve function. Magnesium also supports energy production, bone health, DNA and protein synthesis, and the normal rhythm of the heart. The mineral is involved in over 600 cellular reactions!
Magnesium works together with calcium to support muscle contraction and relaxation. It helps blood vessels dilate (open wider) to improve blood flow. Magnesium may also prevent spasms in blood vessels that can lead to increased blood pressure. The mineral acts as a natural calcium channel blocker, which means it blocks the uptake of calcium by cells in artery walls to help blood vessels relax.
How might magnesium help lower high blood pressure?
Research suggests that getting enough magnesium may help keep blood pressure in a healthy range in several ways, including:
- Acting as a natural calcium channel blocker to promote blood vessel relaxation and improve blood flow
- Helping blood vessels dilate so the heart doesn’t have to pump against as much pressure
- Reducing inflammation in arteries
- Improving insulin sensitivity
- Helping the body synthesize nitric oxide, a compound that dilates blood vessels
According to a meta-analysis of 34 clinical trials published in Hypertension, supplemental magnesium resulted in a significant reduction in systolic and diastolic blood pressure, especially for people with hypertension. Other research shows that higher dietary magnesium intake is associated with a lower risk of developing high blood pressure over time.
How much magnesium do you need per day?
The Recommended Dietary Allowance (RDA) for magnesium is:
- Men age 19-30: 400 mg per day
- Men age 31+: 420 mg per day
- Women age 19-30: 310 mg per day
- Women age 31+: 320 mg per day
However, many experts believe the RDA is too low and recommend getting 420-480 mg per day for general health. Older adults may require more magnesium since absorption tends to decrease with age. For high blood pressure specifically, the dosage used in clinical studies ranges from 365-450 mg per day.
What foods are high in magnesium?
The best sources of magnesium from foods include:
- Dark leafy greens like spinach, Swiss chard, turnip greens, kale
- Nuts and seeds like pumpkin seeds, almonds, cashews
- Fish like mackerel, salmon
- Beans and lentils
- Avocados
- Bananas
- Whole grains
Most people can meet their magnesium needs by eating a balanced diet rich in these foods. However, the typical Western diet is often low in magnesium, so supplementation may be helpful.
Types of magnesium supplements
There are several forms of magnesium supplements available. Here is a comparison of the most common types:
| Type | Bioavailability | Laxative Effect | Price |
|---|---|---|---|
| Magnesium glycinate | High | Low | Moderate |
| Magnesium citrate | Moderate | Moderate | Low |
| Magnesium oxide | Low to moderate | Low | Low |
| Magnesium chloride | High | High | High |
| Magnesium orotate | High | Low | High |
| Magnesium taurate | Moderate | Low | Moderate |
As you can see, magnesium supplements vary in how well they are absorbed by the body (bioavailability), their tendency to have a laxative effect, and cost. Here are some key differences:
- Magnesium glycinate – This chelated form has excellent bioavailability and little laxative effect, making it one of the best forms for high blood pressure. It’s also gentle on the stomach.
- Magnesium citrate – This supplement has moderate bioavailability. It tends to have more of a laxative effect at higher doses but is inexpensive.
- Magnesium oxide – One of the most common forms, magnesium oxide is inexpensive but not well absorbed. It may require high doses to be effective.
- Magnesium chloride – Magnesium chloride has good bioavailability but a significant laxative effect. It also tends to be more expensive.
- Magnesium orotate – This form has good bioavailability and low laxative effect. However, it’s generally more expensive.
- Magnesium taurate – Magnesium taurate has moderate absorption but supports heart health. It has low laxative effects.
Which type of magnesium is most recommended?
Based on its superior bioavailability and low incidence of digestive side effects, magnesium glycinate is often recommended as the best form of magnesium for high blood pressure and overall health. Magnesium citrate may also be effective and is inexpensive.
Magnesium oxide is commonly found in grocery stores and pharmacies, but only has about 4% bioavailability. While it’s cheap, a large dose may be required to lower blood pressure compared to chelated forms like magnesium glycinate. However, magnesium oxide may be a good option for constipation relief.
How to choose a quality magnesium supplement
When shopping for a magnesium supplement, keep these tips in mind:
- Choose chelated forms like magnesium glycinate, magnesium citrate, magnesium taurate, or magnesium orotate for better absorption
- Avoid magnesium sulfate, which can have significant laxative effects
- Look for supplements with 100-400 mg elemental magnesium per serving
- elemental magnesium shows how much actual magnesium is provided per serving
- Capsules typically have higher magnesium content than tablets
- Buy from reputable brands and read customer reviews
- Magnesium may interact with certain medications so speak with your doctor first
What’s the optimal magnesium dosage for high blood pressure?
Clinical studies have used magnesium doses from 365-450 mg per day to lower high blood pressure. The dose depends on the formulation, with forms like magnesium oxide requiring higher doses to provide enough elemental magnesium.
Start at the low end of the dosage range and work up to the maximum based on your health needs. Don’t exceed the Upper Tolerable Intake Level of 350 mg per day from supplemental sources unless advised by your doctor.
Take your daily magnesium dose in divided servings with meals to improve absorption and minimize laxative effects. For blood pressure, taking one dose before bed may optimize levels during the early morning hours when heart attack risk is highest.
Monitor your blood pressure for several weeks or months to determine the minimum effective dose for you. Magnesium is most helpful for people with high blood pressure, but can also support healthy blood pressure levels.
Other lifestyle tips to reduce high blood pressure
While magnesium supplements may help lower high blood pressure, it’s important to make other lifestyle changes to reduce your risk of heart disease and stroke:
- Follow a heart-healthy diet high in fruits, vegetables, whole grains, lean protein, nuts and healthy fats
- Limit processed foods, salt, sugar, refined carbs, and saturated and trans fats
- Maintain a healthy weight for your height
- Exercise regularly with a mix of cardio and strength training
- Limit alcohol to 1 drink per day max for women, 2 for men
- Quit smoking and avoid secondhand smoke
- Manage stress through meditation, yoga, therapy, or other relaxation techniques
- Get enough sleep; aim for 7-9 hours per night
- Monitor blood pressure regularly and take medications as directed
The bottom line
Magnesium is an essential mineral that may help lower high blood pressure through several mechanisms. Getting enough magnesium from foods or supplements can be a safe, effective addition to other lifestyle changes to keep your blood pressure in a healthy range.
Of the available forms of supplemental magnesium, magnesium glycinate provides the highest bioavailability with low risk of laxative effects. A daily dose of 365-450 mg elemental magnesium has been used in studies that demonstrate reductions in blood pressure over 2-24 weeks of treatment.
Magnesium supplements are especially useful for those with hypertension, but can also promote healthy blood pressure levels when combined with dietary and lifestyle changes. Work with your doctor to determine if magnesium supplementation is appropriate as part of your heart health regimen.
