Glutathione’s effects on skin appearance

A 2017 randomised double-blind clinical trial has demonstrated glutathione’s potential skin anti-ageing effects when supplemented orally [1].

Two forms of glutathione were used in the trial – the reduced form of glutathione (GSH) and the oxidised form (GSSG). The study was conducted in 57  females aged 20-50 years over a 12-week period (18 GSSG, 19 GSH, 20 placebo) [1] . 

At a dose of 250mg/d,  GSH (Setria®) and GSSG (AquaGluta™) were shown to display skin lightening efficacy, as measured by the melanin index. Ultraviolet spots of the face and arms were also lowered and skin elasticity was improved, when compared to placebo. Glutathiones ability to increase skin elasticity in both sun-protected and sun-exposed skin was a new finding, with further studies in larger populations warranted [1]. 

GSH only was also shown to significantly reduce wrinkles in certain body locations. The study’s authors state that the ability of GSH to reduce wrinkles was a novel and extremely interesting finding, particularly based on the ageing population. They cite the benefits of simply taking a pill compared to the process and cost of applying topical anti-wrinkle cream to the body [1].

In vitro studies have shown that glutathione displays anti-melanogenic properties possibly initiated via its antioxidant effects and interference of intracellular transport of melanogenic enzymes [2, 3]. A study conducted on ageing mice fed dietary GSH additionally demonstrated T-cell mediated immune response enhancements [4]. These proposed mechanisms may help to explain glutathione’s beneficial effects on skin appearance within the aforementioned studies.

[1] Weschawalit S., Thonghip T., Phutrakool P., Asawanonda P. (2017) Glutathione and its antiaging and antimelanogenic effects, Clinical Cosmetic and Investigational Dermatology (10), 147 – 153. 

[2] Villarama C., Maibach H. (2005) Glutathione. As a depigmenting agent: an overview, International Journal of Cosmetic Science 27 (3), 147 – 153.

[3] Nakajima H., Nagata T., Imokawa G. (2014) Reduced glutathione disrupts the intracellular trafficking of tyroinase and tyrosine-related protein-1 but not dopachrome tautomerase and Pmel17 to melanosomes, which results in the attenuation of melanization, Archives of Dermatological Research, 306 (1), 37 – 49.

[4] Furukawa T., Meydani S., Blumberg J. (1987) Reversal of age-associated decline in immune responsiveness by dietary glutathione supplementation in mice, Mechanisms of Ageing and Development, 38 (2), 107 – 117.

Magnesium’s impact on exercise performance

Magnesium (Mg) is a vital mineral for the human body. Mg holds an essential role as a cofactor in energy metabolism where it binds with adenosine triphosphate (ATP) forming the Mg-ATP complex, a key energy source [1,10].

A systematic review of the literature on Mg status and its impact on exercise performance indicates that a reciprocal relationship exists in the body [2,10]. As physical levels of activity increase, so does the body’s need for Mg. For example, to support exercise function during long and sustained periods of activity such as marathon running, serum Mg shifts to muscles or red blood cells [3,10]. Conversely, during shorter bouts of exercise, serum Mg is increased due to the depletion of serum / plasma volume [3,10].

Additional studies reveal that Mg serum levels correlate positively with muscle performance in male athletes and the elderly [4,5,6,10]. When serum Mg is lacking, neuromuscular function may become impaired, leading to muscle cramps [7,10]. This however hasn’t been proven in exercise-derived cramping [7,10].

A review of animal studies shows Mg supplementation may enhance exercise performance by improving energy metabolism efficacy [8,9,10].  Exercising gerbils and rodents supplemented with Mg displayed a marked rise in plasma glucose that led to increased glucose availability during this active period. [8.9.10]  Improvements in lactate accumulation were also noted [8,9,10]. Furthermore, plasma glucose was retained at a higher level post-exercise, indicating Mg may assist with tissue recovery following exercise [9,10].

Human studies linking Mg supplementation to exercise performance have reported inconsistent results, however the overall consensus is that Mg may improve both aerobic and anaerobic exercise parameters [10]. One 4-week randomised controlled trial divided healthy adult volunteers into three groups  (Mg supplemented group; Mg supplemented + Tae-Kwan-Do training group and a Tae-Kwan-Do training group). The trial showed that Mg improved exercise performance, due to its ability to decrease lactate accumulation [10,11].

The systematic review also noted that the general population, including athletes, were generally Mg deficient [2,10]. This is compounded by the fact that the body’s Mg needs are increased during exercise, thus physically active people may have higher Mg requirements [2,10,12]. Mg deficiencies have been shown to compromise exercise performance in strength training programs, whilst increased Mg intakes in aerobic exercises related to decreased oxygen needs [10,13,14,15]. These findings suggest that Magnesium does have an impact on exercise performance. 

[1] Mildvan, A.S. Role of magnesium and other divalent cations in ATP-utilizing enzymes. Magnesium 1987, 6, 28–33.
[2] Nielsen, F.H.; Lukaski, H.C. Update on the relationship between magnesium and exercise. Magnes. Res. 2006, 19, 180–189.
[3] Bohl, C.H.; Volpe, S.L. Magnesium and exercise. Crit. Rev. Food Sci. Nutr. 2002, 42, 533–563.
[4] Dominguez, L.J.; Barbagallo, M.; Lauretani, F.; Bandinelli, S.; Bos, A.; Corsi, A.M.; Simonsick, E.M.; Ferrucci, L. Magnesium and muscle performance in older persons: the InCHIANTI study. Am. J. Clin. Nutr. 2006, 84, 419–426
[5] Santos, D.A.; Matias, C.N.; Monteiro, C.P.; Silva, A.M.; Rocha, P.M.; Minderico, C.S.; Bettencourt Sardinha, L.; Laires, M.J. Magnesium intake is associated with strength performance in elite basketball, handball and volleyball players. Magnes. Res. 2011, 24, 215–219.
[6] Matias, C.N.; Santos, D.A.; Monteiro, C.P.; Silva, A.M.; Raposo Mde, F.; Martins, F.; Sardinha, L.B.; Bicho, M.; Laires, M.J. Magnesium and strength in elite judo athletes according to intracellular water changes. Magnes. Res. 2010, 23, 138–141.
[7] Garrison, S.R.; Allan, G.M.; Sekhon, R.K.; Musini, V.M.; Khan, K.M. Magnesium for skeletal muscle cramps. Cochrane Database Syst. Rev. 2012.
[8] Cheng, S.M.; Yang, L.L.; Chen, S.H.; Hsu, M.H.; Chen, I.J.; Cheng, F.C. Magnesium sulfate enhances exercise performance and manipulates dynamic changes in peripheral glucose utilization. Eur. J. Appl. Physiol. 2010,108, 363–369
[9] Chen, Y.J.; Chen, H.Y.; Wang, M.F.; Hsu, M.H.; Liang, W.M.; Cheng, F.C. Effects of magnesium on exercise performance and plasma glucose and lactate concentrations in rats using a novel blood-sampling technique.  Appl. Physiol. Nutr. Metab. 2009, 34, 1040–1047.
[10] Zhang, Y; Xun, P; Wang, R; Mao, L; He, K. Can Magnesium Enhance Exercise Performance? Nutrients. 2017, 9.
[11] Cinar, V.; Nizamlioglu, M.; Mogulkoc, R. The effect of magnesium supplementation on lactate levels of sportsmen and sedanter. Acta Physiol. Hung. 2006, 93, 137–144.
[12] Rayssiguier, Y.; Guezennec, C.Y.; Durlach, J. New experimental and clinical data on the relationship between magnesium and sport. Magnes. Res. 1990, 3, 93–102.
[13] Brilla, L.R.; Haley, T.F. Effect of Magnesium Supplementation on Strength Training in Humans. J. Am. Coll. Nutr. 1992, 11, 326–329.
[14] Lukaski, H.C. Vitamin and mineral status: effects on physical performance. Nutrition 2004, 20, 632–644.
[15] Finstad, E.W.; Newhouse, I.J.; Lukaski, H.C.; McAuliffe, J.E.; Stewart, C.R. The effects of magnesium supplementation on exercise performance. Med. Sci. Sports Exerc. 2001, 33, 493–498.

Photo by Jenny Hill on Unsplash