Magnesium Supplements Benefits | Reduce Diabetes Risk?

Written by Dr. Steve Chaney on . Posted in current health articles, Food and Health, Supplements and Health

Author: Dr. Stephen Chaney

 

reduce diabetes riskI came across an article the other day suggesting that one of the magnesium supplements benefits might be  improved blood sugar control in pre-diabetics with low blood levels of magnesium (Guerrero-Romero et al, Diabetes & Metabolism, 41: 202-207, 2015). Considering that…

  • A 2014 CDC report stated that 1/3 of adult Americans are pre-diabetic, and…
  • Most people with pre-diabetes will go on to develop type 2 diabetes in 10 years or less, and…
  • Diabetes is the 7th leading cause of death in this country, and…
  • 60% of Americans don’t get enough magnesium in their diets…

…this could be a really big deal! Because of this I scrutinized the paper very carefully and reviewed the literature on magnesium intake and the incidence of type 2 diabetes.

 

Do Magnesium Supplements Improve Blood Sugar Control?

This was a relatively small study (116 adults, age 30-65), but it was well designed. All of the subjects had mild impairments in blood sugar control (i.e. were pre-diabetic), and all of them had low blood magnesium levels (≤1.8 mg/dL). This is a significant improvement over most previous studies of magnesium supplementation and blood sugar control because blood magnesium levels were not determined in many of those studies.

magnesium supplements benefitsThe study was double-blind, placebo controlled.Subjects received either 382 mg of magnesium or a placebo each day for 16 weeks, at which time blood sugar control and blood magnesium levels were re-measured. All subjects were put on a weight maintenance diet consisting of 55% healthy carbohydrates, 25% healthy fats, and 20% healthy proteins and told to exercise for at least 30 minutes three times per week.

Adherence to the diet and exercise regimen was 91% in both the supplement and placebo groups. Adherence to magnesium supplementation was 85% as measured by an increase in blood magnesium levels.

At the end of 16 weeks:

  • Improvement in blood sugar control was observed in 50% of the people in the magnesium group compared to 7% in the placebo group. This was significantly different.
  • Triglyceride levels were significantly decreased while HDL and blood magnesium levels were significantly increased in the magnesium group compared to the placebo group.
  • Side effects of magnesium supplementation were mild abdominal pain (7.6%) and diarrhea (6.0%).

The authors concluded:

  • “Our present results demonstrate the efficacy and safety of magnesium supplementation in the reduction of plasma glucose levels and in the improvement of glycemic status [blood sugar control] of pre-diabetic individuals who have low serum magnesium levels.”
  • “Our results support the hypothesis that, as a complement to lifestyle intervention programs, people with pre-diabetes and low blood levels of magnesium also should take magnesium supplements to decrease plasma glucose levels and potentially decrease the transition rate from pre-diabetes to diabetes.”

Magnesium and Blood Sugar Control

reduce blood sugarWhile the results of the recent study were impressive, it was a single, relatively small study, so I did a thorough review of the literature to put this study in perspective. This is what I found:

  • A major study that followed 2,582 participants enrolled in the Framingham Heart Study for 7 years (Hruby et al., Diabetes Care, 37: 419-427, 2014) concluded that those who consumed the most magnesium (400 mg/day) had a 50% reduction in the risk of developing type 2 diabetes compared to those who consumed the least (240 mg/day).

Several other studies comparing magnesium intake to diabetes risk have come to similar conclusions.

  • A meta-analysis of 13 studies with 536,318 people (Dong et al, Diabetes Care, 34: 2116-2122, 2011) concluded that the risk of diabetes was decreased by 14% for every 100 mg of magnesium consumed.
  • Most, but not all, intervention studies like the one described above have shown that magnesium supplementation reduced blood glucose levels and improved blood sugar control.

However, most of these studies did not measure blood magnesium levels. This is a significant drawback because if the majority of subjects in a particular study had adequate blood magnesium levels at the beginning of the study, one would not expect additional magnesium to improve blood sugar control.

  • A study of 4257 participants in the 1999-2000 National Health and Nutrition Examination Survey (Ford &Mokdad, Journal of Nutrition, 133: 2879-2882, 2003) concluded that around 60% of the adult US population was getting sub-optimal levels of magnesium from their diet.

The RDAs for magnesium range from 310-420 mg/day depending on age and gender, while intakes of magnesium ranged from 144-326 mg/day depending on age, gender and ethnicity. Those taking supplements had significantly greater magnesium intake than non-supplement users.

However, dietary recall studies almost always overestimate the percentage of the population that is deficient in any particular nutrient. Blood nutrient levels are usually considered a better indicator of nutrient deficiency, and some experts estimate that 20-30% of the US population may have blood levels of magnesium that are less than optimal.

Unfortunately, in the case of magnesium it is unclear whether even blood levels are an adequate indicator of nutrient status. That’s because only 1% of your body’s magnesium is found in the blood. The rest is locked up in your tissues where it is much more difficult to determine whether your magnesium status is adequate or not.

 

The Bottom Line

  • A recent study showed that magnesium supplementation improves blood sugar control in pre-diabetics with low blood magnesium levels. The authors concluded that magnesium supplementation along with lifestyle change may be effective in slowing the progression from pre-diabetes to type 2 diabetes.
  • This study is consistent with a number of previous studies suggesting that increased magnesium intake is associated with decreased risk of developing type 2 diabetes.
  • This study is also consistent with the principle that supplementation works best in situations where there is a demonstrated need for a particular nutrient, in this case magnesium (the study participants were selected in part on the basis of low blood levels of magnesium).
  • Other studies have shown that around 60% of the population is getting inadequate magnesium from their diet.Dietary recall studies probably overestimate the percentage of the population that is magnesium deficient, but most experts agree that a significant percentage of the US population likely have less than optimal magnesium status.
  • You probably don’t need mega-doses of magnesium to support good blood sugar control. The clinical study described above used 382 mg/day of magnesium, but most dietary recall studies suggest that dietary intake of magnesium in this country is only 100-200 mg/day below RDA recommendations.
  • Assuring an adequate intake of magnesium is only one component of a holistic approach for reducing the risk of developing type 2 diabetes. Other important components are weight control, exercise, and a healthy diet that restricts sugars and starches.
  • Good dietary sources of magnesium include leafy green vegetables (5-6 servings = RDA), nuts (5-6 servings = RDA), orwhole wheat bread or brown rice (8-9 servings = RDA).
  • Supplementation with ≥300 mg of magnesium can cause gas, bloating and diarrhea in sensitive individuals. If you are supplementing with magnesium, I recommend a sustained release supplement.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (4)

  • MJ Lucas

    |

    Great info to share Dr. Cheney.

    MJ

    Reply

  • Bill Dunstan

    |

    The results of the study do not indicate the bio absorption of the supplementation that was given the participants over the eight year period. And did they compare different companies prior to the initiation of the study for the best bio absorbency of their supplements?

    Reply

    • Dr. Steve Chaney

      |

      Dear Bill,

      Magnesium salts are very soluble in water, so their bioavailability is generally high and relatively independent of the type of magnesium salt used in the supplement. Your question would be much more pertinent to calcium supplements.

      Dr. Chaney

      Reply

  • Carol Pontius

    |

    Very interesting….. as usual!! Thanks for ALL your good information!

    Reply

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Latest Article

Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the study, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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