 A new study suggests that NMN supplementation can indeed elevate NAD levels and increase walking distance in healthy participants. Not only that, but the study narrowed in on 600 mg a day as the optimal dose. While it is believed that NAD can be supplemented by precursors such as NMN, this route has a few roadblocks. For instance, studies do not always show that NAD precursors increase NAD levels. Their safety is a bit of concern as well, since NAD can provide energy to cancer cells. However, NAD precursors are generally considered safe. This new study was based on a randomized, multi-center, double-blind, placebo-controlled clinical trial that was co-sponsored by two companies that jointly produced a food-grade NMN product. The primary endpoint was NMN's ability to elevate NAD blood levels with secondary endpoints of safety and tolerability, physical performance in a walking test, blood biological age, insulin resistance, and overall health via a subjective assessment. Previous studies were often inconsistent in showing NMN's health benefits or its ability to increase NAD levels in blood. These studies were often sex-biased or conducted in people with pre-existing health conditions. This time, the researchers made it a point of recruiting 80 healthy men and women aged 40 to 65 with a wide range of BMI scores. Three different doses of NMN were investigated, 300, 600, and 900 mg a day. NAD levels were increased significantly in all groups compared to placebo and baseline. There was also a significant difference between 300 and 600 mg a day, but not between 600 and 900. Interestingly, most of the increase in NAD levels happened during the first 30 days of the study, with the second month showing only a very mild additional increase. The 6 minute walking distance at baseline was about 300 meters across the groups, which is on the slower side. It significantly improved in the three study groups compared to placebo and baseline. Here too, the difference between 300 and 600 mg a day was large, but the difference between 600 and 900 was virtually non-existent. The gains in walking distance were substantial, with both the 600 and the 900 mg a day group adding about 150 meters, a 50% increase. Participants were not required to perform any regular physical activity, and testing was done only three times, at baseline, after the first month, and after the second month. If there was any habituation to the walking test, it should have been noticeable in the placebo group. However, in this group, no increase in walking distance occurred. However, it is possible that participants on NMN began feeling more invigorated early into the study period, and increased their physical activity accordingly, which led to better results measured in the clinic. The participants were also asked to complete a 36 question health and quality of life questionnaire. The scores mostly followed the same dynamic as NAD levels and walking distance. There was some increase in the 300 mg a day group compared to placebo, and a much more pronounced increase in both the 600 and 900 mg groups. However, there was no significant difference between the two latter groups. This study appears to establish 600 mg a day of NMN as a preferred dose that significantly impacts NAD levels and physical performance. As with previous NMN studies, no safety problems were reported. However, that does not prove the safety or efficacy of NMN beyond any doubt. Therefore, there should be more studies, with larger sample sizes, different end points, and longer follow up periods. So is NMN a part of your longevity strategy? And will this study change how you view it? Let us know your thoughts in the comments below. When there's more to share, we'll have it for you here, so please subscribe so you don't miss out. I'm Ryan O'Shea and we'll see you next time on Lifespan News.