Exploring the Impact of Alternative Sources of Dietary Nitrate Supplementation on Exercise Performance

An increase in the level of nitric oxide (NO) plays a key role in regulating the human cardiovascular system (lowering blood pressure, improving blood flow), glycemic control in type 2 diabetes, and may help enhance exercise capacity in healthy individuals (including athletes). This molecule is formed by endogenous enzymatic synthesis and the intake of inorganic nitrate (NO3-) from dietary sources. Although one of the most well-known natural sources of NO3- in the daily diet is beetroot (Beta vulgaris), this review also explores other plant sources of NO3- with comparable concentrations that could serve as ergogenic aids, supporting exercise performance or recovery in healthy individuals. The results of the analysis demonstrate that red spinach (Amaranthus spp.) and green spinach (Spinacia oleracea) are alternative natural sources rich in dietary NO3-. The outcomes of the collected studies showed that consumption of selected alternative sources of inorganic NO3- could support physical condition. Red spinach and green spinach have been shown to improve exercise performance or accelerate recovery after physical exertion in healthy subjects (including athletes).

Selective androgen receptor modulator use and related adverse events including drug-induced liver injury: Analysis of suspected cases

PURPOSE

Selective androgen receptor modulators (SARMs) have demonstrated agonist activity on the androgen receptor in various tissues, stimulating muscle mass growth and improving bone reconstruction. Despite being in clinical trials, none has been approved by the Food and Drug Administration (FDA) or European Medicines Agency for pharmacotherapy. Still, SARMs are very popular as performance-enhancing drugs. The FDA has issued warnings about the health risks associated with SARMs, but the long-term exposure and possible adverse events still need to be fully understood. This review aims to evaluate the adverse events associated with using SARMs by humans.

METHODS

PubMed database was searched from September 16, 2022, to October 2, 2023. In total, 20 records were included in the final review. Data from preclinical and clinical studies supported the review.

RESULTS

Since 2020, 20 reports of adverse events, most described as drug-induced liver injury associated with the use of SARM agonists, have been published. The main symptoms mentioned were cholestatic or hepatocellular liver injury and jaundice. Limited data are related to the dosages and purity of SARM supplements.

CONCLUSION

Promoting SARMs as an anabolic agent in combination with other performance-enhancing drugs poses a risk to users not only due to doping controls but also to health safety. The lack of quality control of consumed supplements makes it very difficult to assess the direct impact of SARMs on the liver and their potential hepatotoxic effects. Therefore, more detailed analyses are needed to determine the safety of using SARMs.