Magnesium is an extremely important mineral for the human body. Well over 300 enzyme functions in the body require magnesium. Without it our muscles could not relax, our mitochondria would struggle to produce energy, we could not properly regulate our blood circulation, and our pancreas could not release insulin. These are only a few of the major functions of magnesium.
The human body is not capable of producing magnesium and therefore must be ingested and is considered an essential micronutrient. Some of the most common sources for magnesium are grain products such as oatmeal, sunflower seeds, nuts, leafy-green vegetables, and even water (if it is mineral rich). While this may seem like an abundance of sources the body absorbs roughly 30-40% of dietary magnesium.
While absorption rate is pretty low, there are some nutrients that can help facilitate the absorption such as Vitamin D and protein. The amount of ingested magnesium also seems to have an inverse relationship with the absorption rate. Those individuals who have a high intake absorb a lower percentage, and individuals who have a lower intake absorb at a higher percentage. In my opinion, the body knows how much magnesium it needs and after it has that amount available, it slows down it's absorption rate. The trick is making sure we are providing enough magnesium to the body on a daily basis. With this being said the recommended daily-intake is 400-420mg for men and 320-360mg for women.
Even though magnesium is found in a wide variety of foods, most people do not get enough through diet alone. Some of the common signs of magnesium deficiency are muscle cramps, headaches or migraines, insomnia, depression, and even issues related to concentration. If these issues are in-fact related to magnesium deficiency, they can be resolved quickly. However, if the deficiency or problem persists long-term it could lead to more serious problems such as damage to heart functions.
Diet is not the only factor in magnesium levels throughout the body. Individuals who regularly exercise, or those who are under physical strain/stress, require more magnesium. The reason for this is two-fold. Magnesium is essential for muscle function and energy production. It is also lost through sweat at a rate of approximately 40mg/L.
College athletes are not known for having the best diets, and with the demands of their sport/training magnesium deficiency is a major concern. Of course, we would like everyone to get their recommended intake from whole and organic foods. Supplementation of magnesium might be the correct choice for someone who isn’t willing to change their diet in order to increase their magnesium intake. Supplementation should be the last option, but if necessary post-workout is likely the best time to take it in order to replenish what was lost through sweat. Due to the active lifestyle of athletes the recommended daily intake should be approximately 600mg.
Magnesium has been studied at great lengths. Through these studies, magnesium has been shown to improve blood pressure, blood sugar, mood, athletic performance, and reduce the risk of heart disease. If you’re interested in research I have listed the resources at the end of this post.
We know that magnesium plays a very important role in the release of insulin from the pancreas. It has also been shown that many people who suffer from type-2 diabetes are deficient in this mineral. High blood pressure as well as high levels on insulin in the body, can increase the amount of magnesium that is excreted through urine. Through research, magnesium has been shown to have a beneficial effect on insulin sensitivity as well as blood sugar control. Individuals with type-2 diabetes were given 300mg of magnesium daily for a 3-month period. After 3 this period the individuals saw significant reductions in fasting, as well as, post meal blood sugar levels compared to a placebo group.
Magnesium supplementation has also been linked with improvements in blood pressure. Individual who were given 350-400mg daily, saw 2-4mm Hg drops in systolic blood pressure as well as 2-3mm Hg drops in diastolic blood pressure.
With all the positive responses to magnesium supplementation, we should also take a look at the side-effects. Generally, magnesium supplementation is completely safe, but as with all supplements you should check with your primary health care provider before taking anything. Magnesium could be detrimental to individuals who are taking diuretics, have pre-existing heart conditions, or are taking antibiotics. As far as side-effects, there is a small chance of gut-related issues, such as diarrhea, if too much magnesium is taken over a short period of time.
The health benefits of magnesium are apparent. The downside is very low and mainly affects a very small population. Being a strength and conditioning professional, I’m interested in the athletic performance benefits that magnesium has been shown to have. I’m going to go over some of the studies that have been conducted on this.
In a study of elite male volleyball players, magnesium supplementation of 350mg/day correlated to a 3cm increase in vertical jump height as well as a significant decrease in lactate production. The interesting thing about this study is that the plasma concentrations of magnesium in the supplemented group was actually much lower than that of the control group.
In another study, originally designed to look at magnesium supplementation and systolic blood pressure, the authors found that while exercise performance was not directly shown to have increased the positive effects magnesium had on blood pressure, it actually improved the rate of recovery and post-exercise blood pressure.
A 1999 study on physically active students, who were given 8mg of magnesium per kilo of body weight, found significant improvements in endurance performance as well as decreased oxygen consumption during sub-maximal work.
A study of male athletes supplemented with 390mg of magnesium per day for 25 days, resulted in an increased peak oxygen uptake and total work output during work capacity tests.
Magnesium is an essential nutrient for the human body. Supplementation is not essential, but for those individuals who struggle to get their recommended daily value through diet alone, supplementation could be an alternative. The health and athletic performance benefits of magnesium are numerous and come with a minimal downside, in a very small population. Magnesium deficiency has been proven to have adverse effects on the human body as well as athletic performance. For these reasons, I recommend looking at your normal diet and determining if you’re getting enough magnesium. If you’re not, see where you can add in some magnesium rich food sources such as sunflower seeds or spinach. If you still can’t find a way to increase your intake enough, then maybe supplementation is worth looking into.
I’ll leave you with a quick list and infographic that lists some magnesium rich foods.
Spinach ~ 155mcg/serving
Swiss Chard ~ 150mcg/serving
Black Beans ~ 120mcg/serving
Almonds ~ 95mcg/serving
Cashews ~ 90mcg/serving
Potatoes ~85mcg/serving
Pumpkin/Sunflower Seeds ~45mcg/serving
Avocado ~40 mcg/serving
Bananas ~35 mcg/serving
Broccoli ~30mcg/serving
In this post I did not cover the various types of magnesium, just the mineral as a whole. If you're interested in learning about various form and their uses check out our other post, Magnesium Part II: 11 Forms & Uses.
Resources:
Barbagallo, M., & Dominguez, L. J. (2015). Magnesium and type 2 diabetes. World journal of diabetes, 6(10), 1152–1157. https://doi.org/10.4239/wjd.v6.i10.1152
Gröber, U., Schmidt, J., & Kisters, K. (2015). Magnesium in Prevention and Therapy. Nutrients, 7(9), 8199–8226. https://doi.org/10.3390/nu7095388
Kass, L., Weekes, J., & Carpenter, L. (2012). Effect of magnesium supplementation on blood pressure: a meta-analysis. European journal of clinical nutrition, 66(4), 411–418. https://doi.org/10.1038/ejcn.2012.4
Mathers, T. W., & Beckstrand, R. L. (2009). Oral magnesium supplementation in adults with coronary heart disease or coronary heart disease risk. Journal of the American Academy of Nurse Practitioners, 21(12), 651–657. https://doi.org/10.1111/j.1745-7599.2009.00460.x
Reyes, A. J., & Taylor, S. H. (1999). Diuretics in cardiovascular therapy: the new clinicopharmacological bases that matter. Cardiovascular drugs and therapy, 13(5), 371-398.
Romani A. (2018). Beneficial Role of Mg2+ in Prevention and Treatment of Hypertension. International journal of hypertension, 2018, 9013721. https://doi.org/10.1155/2018/9013721
Tarleton, E. K., Littenberg, B., MacLean, C. D., Kennedy, A. G., & Daley, C. (2017). Role of magnesium supplementation in the treatment of depression: A randomized clinical trial. PloS one, 12(6), e0180067. https://doi.org/10.1371/journal.pone.0180067
Volpe, Stella Lucia PhD, RD, LDN, FACSM Magnesium and the Athlete, Current Sports Medicine Reports: July/August 2015 - Volume 14 - Issue 4 - p 279-283 doi: 10.1249/JSR.0000000000000178
Zhang, Y., Xun, P., Wang, R., Mao, L., & He, K. (2017). Can Magnesium Enhance Exercise Performance?. Nutrients, 9(9), 946. https://doi.org/10.3390/nu9090946