ZMA (supplement)
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ZMA (zinc monomethionine aspartate, magnesium aspartate and vitamin B6) is a supplement marketed towards athletes, gymnasts, and bodybuilders. It was developed by Victor Conte (founder of BALCO Laboratories in Burlingame, California). “Effects of a Novel Zinc-Magnesium Formulation on Hormones and Strength” is the title of a study by L.R. Brilla and Victor Conte published in Journal of Exercise Physiologyonline, 2000, 3(4):26-36. This study launched ZMA into elite Sports Nutrition due to the quality of ZMA ingredients, the timing of dosing, and the quality of the Brilla study.[1]
Formula
[edit]The ZMA formula is composed of zinc monomethionine aspartate (30 mg), magnesium aspartate (450 mg), and vitamin B6 as pyridoxine hydrochloride (10.5 mg). The manufacturer recommends that ZMA be taken 30 – 60 minutes before bedtime with an empty stomach to help synchronize absorption with sleep. The product should not be taken with foods or supplements containing calcium because calcium blocks the absorption of zinc.[2]
While ZMA is a registered trademark of SNAC Nutrition, a subsidiary of SNAC System Inc., ZMA is not a patented formula and other manufacturers can produce supplements using the same formula. Variations on the formula include ZMA-5 (ZMA formula with 5-Hydroxytryptophan), marketed as a sleep enhancer, and ZMA Nightcap, marketed as anabolic mineral support. Like all 5-HTP-containing supplements, serotonin levels may be increased- affecting sleep appetite and temperature. [3]
Scientific studies
[edit]A 1998 study was performed on NCAA football players during an 8-week spring training program. Those who took the ZMA tablets claimed greater increases in muscle strength.[4] However, the study was funded by SNAC Systems Inc, which controls the trademark for ZMA. One of the study's authors, Victor Conte, has ownership equity in SNAC System Inc. company.
In 2004, supplement company Cytodyne funded a study on 42 resistance-trained males using a product called Z-Mass PM that contained ZMA and additional ingredients Mucuna pruriens and polypodium vulgare. The study found that Z-Mass PM supplementation had no significant effects on total and free testosterone, IGF-1, growth hormone, cortisol, the ratio of cortisol to testosterone, or muscle and liver enzymes in response to training. No significant effects were observed in changes in strength, upper or lower body muscle endurance, or anaerobic sprint capacity.[5] However, the researchers of this second study failed to consider that the product they were testing contained Mucuna pruriens, an ingredient rich in phytic acids (phytate). Phytates are well known to interfere with the absorption of zinc and magnesium. Zinc and magnesium are principal ingredients in ZMA. Both minerals are easily affected in terms of how well they are absorbed in the body. Thus, the formula of the product Z-Mass PM was poorly designed if the intent was to showcase potential benefits of ZMA. [6]
In another study done in 2006, a team of German scientists measured the effect of ZMA on testosterone levels.[7] The study found that ZMA altered urine color due to increased secretion of zinc. It found no effect on testosterone levels.
References
[edit]- ^ https://www.asep.org/asep/asep/BrillaV2.PDF
- ^ "High dietary calcium intakes reduce zinc absorption and balance in humans". Retrieved 2016-03-01.
- ^ https://www.webmd.com/vitamins/ai/ingredientmono-794/5-htp
- ^ Brilla, L; Conte, V (October 2000). "Effects of a Novel Zinc-Magnesium Formulation on Hormones and Strength". Journal of Exercise Physiology Online. 3 (4): 26–36.
- ^ Wilborn, Colin D; Kerksick, Chad M; Campbell, Bill I; Taylor, Lem W; Marcello, Brandon M; Rasmussen, Christopher J; Greenwood, Mike C; Almada, Anthony; Kreider, Richard B (2004). "Effects of Zinc Magnesium Aspartate (ZMA) Supplementation on Training Adaptations and Markers of Anabolism and Catabolism". Journal of the International Society of Sports Nutrition. 1 (2): 12–20. doi:10.1186/1550-2783-1-2-12. PMC 2129161. PMID 18500945.
- ^ https://nutritionsource.hsph.harvard.edu/anti-nutrients/#:~:text=Phytates%20(phytic%20acid)%20in%20whole,legumes%E2%80%94can%20decrease%20iron%20absorption.
- ^ Koehler, K; Parr, M K; Geyer, H; Mester, J; Schänzer, W (2007). "Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement". European Journal of Clinical Nutrition. 63 (1): 65–70. doi:10.1038/sj.ejcn.1602899. PMID 17882141.