Minerals for active people: magnesium
Magnesium participates in over 300 metabolic processes in the body and is an enzyme activator. It works in association with sodium, potassium, and calcium with which it needs to maintain a certain level of balance within the organism. About half of the body’s magnesium is found in bones and teeth whilst the rest is situated in the muscles, the liver and other soft tissues.
An essential mineral for solid bones and teeth, magnesium also helps with the proper function of muscles by supporting neurotransmission. Furthermore, it helps in the formation of tissues.
Deficiency amongst athletes
Did you know that 72 % of men and 77 % of women do not get enough magnesium? It would seem that modern diets which are more and more sophisticated, the soils which are become depleted of minerals and growing levels of stress are exposing us to magnesium deficiency. Certain factors also increase these odds such as alcohol abuse, aging, Crohn’s disease, celiac disease, other digestive issues and certain medications such as antibiotics all increase magnesium deficiency.
Magnesium deficiency often occurs in athletes due to increased loss through perspiration, particularly in the summer, as well as different metabolic processes that increase urine and fecal losses. The increased losses combined with the already low magnesium levels in our diet mean that we need to be even more vigilant in order to avoid crashing magnesium levels in our body.
CONSEQUENCES OF MAGNESIUM DEFICIENCY
The consequences of magnesium deficiency are numerous and often result in:
- a significant decrease in athletic performances;
- lower recovery times;
- difficulty contracting muscles (tetany, cramps, muscle pain);
- reduced muscle relaxation after contraction;
- lowered tolerance to heat;
- exacerbated oxidative stress;
- premature accumulation of acid in muscles.
Stress increases magnesium loss through the kidneys which in turn leads to hypomagnesemia (an abnormally low level of magnesium in the blood) which then creates stress. And that is the beginning of a vicious cycle! Therein lays the importance of compensating with an important supply of magnesium (1). Intense effort, especially during high heat, can lead to eliminating up to 30 mg per litre of perspiration (2).
Estimates show that a deficiency can occur with magnesium intake under 220 mg/day for female athletes and 260 mg/day for men. Athletes with the highest risks are those that practice gymnastics, boxing, judo and weight lifting. Some restrict calorie intake and consequently magnesium intake (1).
Researchers at the Children’s Hospital and Research Center Oakland confirm that the aging of cells in the human body is accelerated by the lack, even by the slightest amount, of magnesium.
MAGNESIUM HAS POSITIVE ACTIONS ON:
- The maintenance of energy production;
- Athletic performances;
- Reduced muscular cramping;
- The protection of muscles (reduction of creatine kinase);
- Physical performances, increased by elevated VO2 max (maximum capacity to consume oxygen);
- The control of cortisone levels and protection against the harmful effects of oxidative stress;
- Neuromuscular hyper excitability;
- Pregnancy (as of the 2nd month, magnesium levels crash);
- The cardiovascular system;
- Nutrient metabolism (calcium, sodium, phosphorus, potassium, vitamins K – C and B, proteins, carbohydrates, enzymes);
HOW TO CHOOSE A GOOD SUPPLEMENT
To absorb minerals, the body must first chelate and then ionise them. A liquid supplement solution is already ionized and bioavailable. It will therefore be assimilated more efficiently compared to other forms of magnesium (crystals, capsules or tablets). Furthermore, liquid magnesium has an ideal isotonic concentration.
Magnesium chloride is the most common form of magnesium. Generally extracted from sea water, it is perfectly soluble and offers a superior performance. It can however be replaced by magnesium sulphate for those who strongly dislike the taste of chlorides.
Sources (1) Nielsen FH, Lukaski HC. Update on the relationship between magnesium and exerc Ford ES. Serum magnesium and ischaemic heart disease: Findings from a national sample of US adults. Intl J of Epidem 1999;28:645-651. Liao F, Folsom A, Brancati F. Is low magnesium concentration a risk factor for coronary heart disease? The Atherosclerosis Risk in Communities (ARIC) Study. Am Heart J 1998;136:480-90. Abbott RD, Ando F, et al. Dietary magnesium intake and the future risk of coronary heart disease (the Honolulu Heart Program).Am J Cardiol. 2003 Sep 15;92(6):665-9. Ascherio A, Rimm EB, et al.Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men Shechter M, Bairey Merz CN, et al. Effects of oral magnesium therapy on exercise tolerance, exercise-induced chest pain, and quality of life in patients with coronary artery disease. Am J Cardiol 2003;91:517-21. Shechter M, Sharir M, et al.Oral magnesium therapy improves endothelial function in patients with coronary artery disease. Circulation 2000;102:2353-58. Texte intégral [Consulté le Gums JG. Magnesium in cardiovascular and other disorders. Am J Health Syst Pharm. 2004 Aug 1;61(15):1569-76. Review. Murakami K, Okubo H, Sasaki S. Effect of dietary factors on incidence of type 2 diabetes: a systematic review of cohort studies. J Nutr Sci Vitaminol (Tokyo). 2005 Aug;51(4):292-310. Review. Song Y, Manson JE, Buring JE, Liu S. Dietary magnesium intake in relation to plasma insulin levels and risk of type 2 diabetes in women.Diabetes Care. 2004 Jan;27(1):59-65. Texte intégral [Consulté le 8 mai 2006] : http://care.diabetesjournals.org Meyer KA, Kishi LH, Jacobs DR Jr et al. Carbohydrates, dietary fiber, and incident type 2 diabetes in older women. Am J Clin Nutr 1999;71:921-30. Texte intégral [Consulté le 8 mai 2006] : http://www.ajcn.org Takaya J, Higashino H, Kobayashi Y. Intracellular magnesium and insulin resistance. Magnes Res. 2004 Jun;17(2):126-36. Review. Barbagallo M, Dominguez LJ, Galioto A, et al. Role of magnesium in insulin action, diabetes and cardio-metabolic syndrome X. Mol Aspects Med. 2003 Feb-Jun;24(1-3):39-52. Review. Shamberger RJ. Calcium, magnesium, and other elements in the red blood cells and hair of normals and patients with premenstrual syndrome. Biol Trace Elem Res. 2003 Aug;94(2):123-9. Walker AF, De Souza MC, et al. Magnesium supplementation alleviates premenstrual symptoms of fluid retention. J Womens Health. 1998 Nov;7(9):1157-65. Fugh-Berman A, Kronenberg F. Complementary and alternative medicine (CAM) in reproductive-age women: a review of randomized controlled trials. Reprod Toxicol. 2003 Mar-Apr;17(2):137-52. Review. Massey L. Magnesium therapy for nephrolithiasis.Magne Res. 2005 Jun;18(2):123-6. Review. Ettinger B, Pak CY, et al. Potassium-magnesium citrate is an effective prophylaxis against recurrent calcium oxalate nephrolithiasis. J Urol. 1997 Dec;158(6):2069-73. Bohl CH, Volpe SL. Magnesium and exercise. Crit Rev Food Sci Nutr. 2002;42(6):533-63. Review. Lukaski HC. Vitamin and mineral status: effects on physical performance. Nutrition. 2004 Jul-Aug;20(7-8):632-44. Review. Newhouse IJ, Finstad EW. The effects of magnesium supplementation on exercise performance. Clin J Sport Med. 2000 Jul;10(3):195-200. Review. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride, 1997, page 200. [Consulté le 21 avril 2005]. www.nap.edu Études mentionnées et résumées dans : Rude RK, Gruber HE. Magnesium deficiency and osteoporosis: animal and human observations. J Nutr Biochem. 2004 Dec;15(12):710-6. Review. Stendig-Lindberg G, Koeller W, et al. Experimentally induced prolonged magnesium deficiency causes osteoporosis in the rat.Eur J Intern Med. 2004 Apr;15(2):97-107. Young GL, Jewell D. Interventions for leg cramps in pregnancy. Cochrane Database Syst Rev. 2002;(1):CD000121. Review. Meier B, Huch R, et al. Does continuing oral magnesium supplementation until delivery affect labor and puerperium outcome?Eur J Obstet Gynecol Reprod Biol. 2005 Dec 1;123(2):157-61. Kozielec T, Starobrat-Hermelin B. Assessment of magnesium levels in children with attention deficit hyperactivity disorder (ADHD).Magnes Res. 1997 Jun;10(2):143-8. Starobrat-Hermelin B, Kozielec T. The effects of magnesium physiological supplementation on hyperactivity in children with attention deficit hyperactivity disorder (ADHD). Positive response to magnesium oral loading test.Magnes Res. 1997 Jun;10(2):149-56. Inna Slutsky, Nashat Abumaria, Long-Jun Wu, Chao Huang, Ling Zhang, Bo Li, Xiang Zhao, Arvind Govindarajan, Ming-Gao Zhao, Min Zhuo, Susumu Tonegawa and Guosong Liu. Enhancement of Learning and Memory by Elevating Brain Magnesium. Neuron, Jan. 28, 2010 Médecine du sport, Jean-Marcel Ferret md, Henri Kaleckar md, Éditions Boiron 2000 http://www.passeportsante.net http://biogassendi.ifrance.com