Minerals Research Update: Metabolic Health, Fertility, and Heart Health

Metabolic Enhancer

The essential mineral magnesium is involved in numerous physiological processes as a cofactor for hundreds of enzymes. Its importance is well known for areas including heart and vascular health, bone health, and overall cellular function.(1)

Recently, Nizal Sarrafzadegan and colleagues from the Isfahan Cardiovascular Research Center in Iran conducted a systematic review and meta-analysis of studies looking at magnesium’s role in metabolic syndrome.(2) Metabolic syndrome includes a constellation of symptoms consisting of poor regulation of blood sugar, blood pressure, and weight gain, and ultimately may increase the risk of heart disease, stroke, and diabetes.

In total, the researchers included nine studies with 31,876 participants assessing dietary magnesium intake and metabolic syndrome risk as well as eight additional studies looking at serum magnesium levels and metabolic syndrome. Their analysis showed that higher magnesium intakes were associated with substantially lower risk of metabolic syndrome (odds ratio of 0.73), indicating that adequate magnesium intake is essential for protecting against various heart-disease risk factors.

References:
1. Minerals. Linus Pauling Institute/Oregon State University. Available at: http://lpi.oregonstate.edu/mic/minerals. Accessed March 13, 2016.
2. Sarrafzadegan N et al., “Magnesium status and the metabolic syndrome: A systematic review and meta-analysis,” Nutrition, vol. 32, no. 4 (April 2016): 409–417

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Heart Balance

Selenium is a mineral that plays a significant role in antioxidant processes in the body due to its presence in selenoproteins. One of the most important families of selenoproteins includes the glutathione peroxidases. These enzymes function to reduce potentially harmful free radicals. Selenium deficiency may make individuals more susceptible to physiological stress. Adequate amounts are essential for efficient physiological function, but excessive amounts may be toxic.(1)

Low activity of glutathione peroxidase enzymes has been reported in heart disease. Therefore, adequate selenium may offer protection against the development of heart conditions. To evaluate this, researchers led by Xi Zhang at Indiana University (Indianapolis, IN) conducted an analysis of data from 16 identified prospective observational and 16 randomized controlled trials.(5) Their analysis of prospective studies showed a significant benefit to heart disease prevention in a narrow range of blood selenium concentrations between 55 and 145 mcg/L.

Their meta-analysis of controlled clinical trials that ranged from 6 to 114 months of selenium supplementation, however, found no effect on heart disease prevention, questioning the benefit of widespread selenium supplementation for heart health. This research indicates that there may be an optimal target range for selenium’s heart-protective benefits, and further studies may focus on determining what this range is.


References:
5. Zhang X et al., “Selenium status and cardiovascular diseases: meta-analysis of prospective observational studies and randomized controlled trials,” European Journal of Clinical Nutrition, vol. 70, no. 2 (February 2016): 162–169

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Fertile Possibilities

Zinc is a required mineral for cellular metabolism. Zinc plays a crucial role in many diverse processes and is essential for immune health, brain function, and reproduction.(1) According to the Mayo Clinic, up to 15% of couples are infertile, while half of these cases may result from male fertility issues.(3)

Jiang Zhao and colleagues from the Department of Urology at the Third Military Medical University in Chongqing, China, performed a meta-analysis to look at zinc levels in seminal plasma and the correlation with male fertility.(4) After a systematic search of databases for published information, the authors identified 20 studies including 2,600 cases and 867 controls. The resulting analysis found that seminal plasma zinc concentrations from infertile males were significantly lower than those from normal controls. They also found that zinc supplementation significantly increased semen volume, sperm motility, and the percentage of normal sperm morphology, confirming the important role of zinc in several parameters of male fertility.

References:
3. Male Infertility. Mayo Clinic. Available at: www.mayoclinic.org/diseases-conditions/male-infertility/basics/definition/con-20033113. Accessed March 13, 2016.
4. Zhao J et al., “Zinc levels in seminal plasma and their correlation with male infertility: A systematic review and meta-analysis,” Scientific Reports. Published online March 2, 2016.

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