Magnesium for Digestive Health

What Do We Know Right Now?

There are two things I never get tired of talking about…

Poop, and magnesium intake.

But does one have anything to do with another?

That question is not as straightforward to answer as you might think.

In today’s article I will explore why magnesium is such a popular mineral and help you understand what, if any, role it has to play in the various aspects of digestive health.

Let’s get right to it.

Magnesium – The Most Popular Mineral?

If not, it’s certainly up there – or it should be.

A quick glance at the top 50 selling supplements on Amazon.com reveals two magnesium-containing supplements and the fact that these products are obviously on consumer’s radar.

Combine that with the population level data suggesting magnesium intake is suboptimal and we have ourselves a story.

In fact, a 2018 paper out of the Open Heart journal described inadequate magnesium intake as a driver of heart disease and public health crisis.

Given magnesium’s role in blood pressure reduction and how common high blood pressure is, combined with the immense nutritional value of magnesium-rich foods, this statement comes as little surprise to me.

We also must consider that higher magnesium intakes have been associated with reduced risk of stroke and type 2 diabetes.

The problem is that magnesium is found in richest supply in some of the most important yet underappreciated food groups.

These include:

• Leafy Greens (chard, kale, spinach)
• Seeds (squash, pumpkin, hemp, flax)
• Legumes (kidney beans, chickpeas, lentils)
• Nuts (almonds, cashews, walnuts)
• Whole grains (brown rice, quinoa)

I consider these food groups, all of which are fiber-rich, to merit daily inclusion when working with clients, but for various reasons these magnesium rich foods often fly under the radar.

As a dietitian, that’s difficult to digest.

But does a lack of magnesium mean your food will be too?

Let’s find out.

Magnesium & Gut Health

The connection between magnesium, both dietary and supplemental, and gut health is not the most straightforward.

Here are some key considerations based on the best available evidence. 

Consideration #1 – Magnesium Oxide & Constipation

Magnesium oxide is a supplemental form of magnesium which is widely available and has been utilized for decades in Japan as a generally safe and low-cost management tool for constipation.

Observational data has suggested that low magnesium intake could be associated with an increased risk of constipation, perhaps in part due to the role magnesium plays as an electrolyte which affects both muscle relaxation and water balance.

A 2019 randomized controlled trial looking at Japanese women with mild to moderate constipation found that 500 mg of magnesium oxide 3x daily improved Bristol score rating and colon transit time (the time for which it takes food to move through the entirety of the digestive tract, which is prolonged in those with constipation).

The American Journal Of Gastroenterology recently concluded that magnesium-based products are supported by moderate evidence as it relates to their use as over the counter constipation aids but certainly populations including those living with renal disease, the elderly and those on multiple-medications may need to proceed with extra caution.

It should also be noted that insufficient evidence exists to make claims about the utility of magnesium supplementation in IBS-C, which naturally follows as an area of interest.

Consideration #2 – Magnesium Intake & GERD-related Considerations

There are indeed a set of intriguing connections between magnesium intake and GERD.

A 2015 study out of the British Journal Of Nutrition identified that higher dietary magnesium intakes were associated with a lower risk of esophagitis (inflammation of the esophagus) and Barrett’s Esophagus – a pair of conditions for which those living with GERD are at higher risk of.

The other issue at hand is that Proton Pump Inhibitors, a medication used for GERD management and  among the most prescribed pharmaceuticals in North America, may compromise magnesium status.

As per a 2019 systematic review and meta-analysis out of Medicine -this is particularly true in the case of long-term and high dose PPI use, which could justify observing magnesium status in people for whom this is true.

Final Thoughts

Magnesium intake and supplementation are novel and emerging areas of inquiry in the worlds of both general public health as well as digestive health in specific contexts.

Given the incredible nutrient density and valuable physiological characteristics of foods rich in magnesium, combined with the fact they tend to be under-consumed, there are a number of ways in which improving magnesium intake could lead to benefits for both digestive and overall health.

Magnesium supplementation, as discussed today, may also have a role to play in this regard but more research will be needed to determine the extent to which it is uniquely useful.