In a paper published in the Journal of the International Society of Sports Nutrition, researchers at Aristotle University of Thessaloniki in Serres Greece reported that rats who received NR tended to show worse physical performance by 35%. There are a number of things to be aware of as you read this study and digest its conclusion.

It is important to understand that:

  • How NR is prepared and delivered matters. Additional questions need to be asked in order to understand exactly what material was delivered to the animals in this study. Was the NR extracted from capsules? Were the capsules broken open? Did it include any other ingredients or excipients? Was the material tested for purity before being used? All of these factors could have the potential to influence the study results, yet as readers, we are unable to discern answers to these questions based on the way the report was written.
  • This was a small study, and yielded results with a wide range of variability. First, there were only a few animals in each group. Given the variability in each groups result, additional animals in each group may have helped limit the variability, providing more reliable information. Next, the study consisted of a single outcome: including just one time point, one outcome measure, one dose, and it used rats that were all 4 months old. This particular design does not permit investigators or readers to consider other influencing factors, or draw conclusions for populations of various ages.
  • There were no statistically significant findings. Both the group receiving nicotinamide riboside and the group which did not receive nicotinamide riboside showed a wide range of variability in their performance. Additionally, there was not a statistically significant difference between the performance of the groups. The conclusion noted by the investigators, that physical performance decreased by 35% in the nicotinamide riboside group, may be an observation within the data, however the difference between groups was not statistically significant, suggesting it could also simply be due to chance.