| Title |
Performance and Side Effects of Supplementation with N-Acetylcysteine: A Systematic Review and Meta-Analysis
|
|---|---|
| Published in |
Sports Medicine, January 2017
|
| DOI | 10.1007/s40279-017-0677-3 |
| Pubmed ID | |
| Authors |
Kate Rhodes, Andrea Braakhuis |
| Abstract |
N-Acetylcysteine (NAC) is a promising antioxidant supplement with potential as an acute strategy to enhance performance in elite sport, but there are concerns about its side effects with high doses. To review the current literature and evaluate the effects of NAC supplementation on sport performance and the risk of adverse effects. The literature up to May 2016 was searched on MEDLINE (PubMed), EMBASE, SPORTDiscus, Google Scholar and Scopus databases to identify all studies investigating the effects of NAC supplementation on exercise performance and/or side effects experienced. Performance outcomes from each study were converted to the percent effect equivalent to mean power output in a time trial. All pooled analyses were based on random-effects models generated by Review Manager (RevMan) [Computer program], version 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, 2014). A total of seven studies met criteria for inclusion in the sport performance meta-analysis, and 17 for inclusion in the side effects meta-analysis. The typical daily dose of NAC reported was 5.8 g·d(-1); with a range between 1.2 and 20.0 g·d(-1). The mean increase in performance was 0.29% (95% confidence interval -0.67 to 1.25). The difference in the odds ratio of side effects on NAC compared with placebo was 1.11 (95% confidence interval 0.88-1.39). The sub-analysis of NAC dose suggested an increase in side effects as the dosage of NAC increased; however, this observation requires further investigation. Despite initial research publications reporting positive performance effects with NAC, at this stage it cannot be recommended further. The risk of side effects from NAC supplementation also remains unclear owing to significant variations in effects. Suboptimal reporting and documentation in the literature creates difficulties when meta-analysing outcomes and generating conclusions. |
X Demographics
The data shown below were collected from the profiles of 15 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| New Zealand | 2 | 13% |
| United Kingdom | 2 | 13% |
| United States | 2 | 13% |
| Taiwan | 1 | 7% |
| Ecuador | 1 | 7% |
| Switzerland | 1 | 7% |
| Spain | 1 | 7% |
| Unknown | 5 | 33% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 6 | 40% |
| Scientists | 6 | 40% |
| Practitioners (doctors, other healthcare professionals) | 3 | 20% |
Mendeley readers
The data shown below were compiled from readership statistics for 109 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 109 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Master | 19 | 17% |
| Researcher | 14 | 13% |
| Student > Bachelor | 13 | 12% |
| Student > Ph. D. Student | 11 | 10% |
| Student > Doctoral Student | 5 | 5% |
| Other | 21 | 19% |
| Unknown | 26 | 24% |
| Readers by discipline | Count | As % |
|---|---|---|
| Sports and Recreations | 18 | 17% |
| Medicine and Dentistry | 17 | 16% |
| Nursing and Health Professions | 12 | 11% |
| Agricultural and Biological Sciences | 9 | 8% |
| Biochemistry, Genetics and Molecular Biology | 8 | 7% |
| Other | 17 | 16% |
| Unknown | 28 | 26% |
Attention Score in Context
This research output has an Altmetric Attention Score of 11. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 13 July 2021.
All research outputs
#3,095,008
of 23,975,876 outputs
Outputs from Sports Medicine
#1,612
of 2,778 outputs
Outputs of similar age
#63,141
of 422,782 outputs
Outputs of similar age from Sports Medicine
#37
of 45 outputs
Altmetric has tracked 23,975,876 research outputs across all sources so far. Compared to these this one has done well and is in the 87th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 2,778 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 52.5. This one is in the 42nd percentile – i.e., 42% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 422,782 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 85% of its contemporaries.
We're also able to compare this research output to 45 others from the same source and published within six weeks on either side of this one. This one is in the 20th percentile – i.e., 20% of its contemporaries scored the same or lower than it.