#419: Nathan Bryan, PhD – Role of Nitric Oxide in Human Health

In Podcasts by Danny Lennon4 Comments

Guest Information


Nathan Bryan, PhD

Dr. Nathan Bryan, PhD is an Adjunct Assistant Professor at Baylor College of Medicine. Dr. Bryan has been involved in nitric oxide research for the past 18 years and has made many seminal discoveries in the field. He was the first to demonstrate and discover an endocrine function of nitric oxide via the formation of S-nitrosoglutathione and inorganic nitrite.

Dr. Bryan obtained his doctoral degree from Louisiana State University School of Medicine in Shreveport where he was the recipient of the Dean’s Award for Excellence in Research. He pursued his post-doctoral training as a Kirschstein Fellow at Boston University School of Medicine in the Whitaker Cardiovascular Institute. After a two year post-doctoral fellowship, in 2006 Dr. Bryan was recruited to join faculty at the University of Texas Health Science Center at Houston by Ferid Murad, M.D., Ph.D., 1998 Nobel Laureate in Medicine or Physiology.

In this episode we discuss:

  1. What NO does within the body
  2. Endogenous production of NO: Nitrate-Nitrite-NO pathway and the Oxidation of L-arginine (NOS) pathway
  3. NO loss and atherosclerosis
  4. Causes of low NO
  5. Impact of mouthwash and antacid
  6. Clinical consequences of low NO production
  7. How do we restore normal NO production?
  8. Nutrition interventions
  9. Do “NO producing” supplements actually work?

Links & Resources

Support the Podcast

If you regularly enjoy listening to Sigma Nutrition Radio and you'd like to take your support even further, then you can officially support the podcast by either making a one-time donation or via a recurring payment. If you wish to do so then you can do so here.
Thank you for considering!


  1. I enjoyed this interview, but left me confused about what NO supplements actually work. Any advice on how to actually find the kinds of supplements that he references?

    1. Author

      Hey Craig,

      In relation for increasing nitrate intake for health reasons, it would have to be from a product that has a guarenteed nitrate content. Some of the more repulatable beet concentrate shots for example, guarentee 400mg per shot. In relation to the lozenge Dr. Bryan discussed, that is used in clinical settings rather than being a commercial product as far as I know.

      Other nitric oxide related supplements have evidence for benefiting sports performance specifically. These are primarily L-citrulline/citrulline malate and the beetroot products mentioned above. However, this depends on the type of exercise, and research can be mixed. Episode 176 with Eric Trexler gets into this more. And I’d recommend more recent articles of his on Stronger By Science website.

  2. really interesting interview, thanks…. no mention of alcohol, however. Given that that is the main ingredient in mouth wash it would seem likely that consuming alcohol would also interfere with the bacterial conversion to NO.

    1. Author

      Hey Sharon,

      Thanks for the comment and the interesting point you make. I’m unsure the alcohol content of most beverages would have the anti-bacterial effect of a mouthwash, but regular alcohol drinking can impact the oral microbiome from what I can recall. Indeed, in alcohol abuse disorder there are significant detrimental changes to the oral microbiome, although that may not all be down to just the alcohol content.

      This is a specific question I’d like to dig into the literature deeper on before giving a full response. As it seems there may be an important aspect to the dose, with low doses not hampering NO production (and even acutely enhancing it): https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC2562584/

      However, I don’t have a complete answer for you right now, so will try to look into the details of this particular issue.

Leave a Comment