Hart2Heart with Dr. Mike Hart by Dr. Mike Hart

August 13, 2026 #233 Understanding NAD+: Insights with Dr. Charles Brenner

Charles Brenner breaks down what the science actually says about NAD+, separating established findings from the claims commonly made in the longevity space. He explains why NAD levels in tissues may matter more than blood measurements, how metabolic stress, alcohol, inflammation, and other conditions can disrupt the NAD system, and how nicotinamide riboside (NR) compares with niacin, nicotinamide, and NMN. The conversation also covers research on exercise recovery, peripheral artery disease, skin health, infection, and wound healing, along with the limitations of current human evidence. Brenner explains why he advises against IV and subcutaneous NAD+, discusses concerns around NMN quality, and challenges popular sirtuin-centered theories of anti-aging while emphasizing the importance of reproducible human research.

Charles Brenner is an NAD metabolism researcher whose work focuses on cellular bioenergetics, vitamin B3 biology, metabolic stress, and the pathways that regulate NAD production and utilization throughout the body. Now based at the University of Helsinki, his research has examined how the NAD system responds to conditions ranging from metabolic and liver disease to mitochondrial dysfunction, inflammation, and neurological stress. His work has also helped advance research into nicotinamide riboside as an NAD precursor and its potential applications in human health. Brenner takes an evidence-first approach to longevity science, distinguishing findings supported by controlled human studies from promising but still unproven mechanisms, animal research, and anecdotal claims.

Brenner Lab — Charles Brenner, PhD

https://www.brennerlab.net/

Niagen NR Clinical Studies — Niagen Bioscience

https://www.niagenbioscience.com/pages/clinical-studies

Nicotinamide Riboside for Peripheral Artery Disease — Mary M. McDermott et al.

https://pubmed.ncbi.nlm.nih.gov/38871717/

This is the PAD study discussed in the episode where NR improved six-minute walking performance.

NOPARK: Nicotinamide Riboside in Early Parkinson's Disease — Haukeland University Hospital / Norwegian Research Team

https://clinicaltrials.gov/study/NCT03568968

This is the 400-participant, 52-week Parkinson's trial discussed in the transcript.

Effects of Nicotinamide Riboside in Long COVID — Chao-Yi Wu, Edmarie Guzmán-Vélez, Charles Brenner et al.

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370%2825%2900567-X/fulltext

This is the Long COVID study Brenner references when discussing cognition, fatigue, sleep, and symptom recovery.

NAD+ Metabolome in Alcohol-Related Liver Disease — Richard Parker, Charles Brenner et al.

https://pubmed.ncbi.nlm.nih.gov/32766477/

This is the human alcohol-related liver disease research Brenner discusses when explaining disturbed liver NAD metabolism.

Nicotinamide for Skin-Cancer Chemoprevention — Andrew C. Chen et al.

https://pubmed.ncbi.nlm.nih.gov/26488693/

This is the major Australian study relevant to Brenner's discussion of oral nicotinamide and skin cancer protection.

Charles Brenner on NAD+, NR vs. NMN & NAD IVs — Dr. Rhonda Patrick / FoundMyFitness

https://www.foundmyfitness.com/episodes/charles-brenner

Dr. Mike specifically references Brenner's appearance with Rhonda Patrick during the episode.

Show Notes

00:00 Welcome to the Hart2Heart Podcast

00:58 NAD Basics Explained

02:22 Cellular Role of NAD

03:21 Proven Benefits and Trials

05:24 Inflammation Markers Deep Dive

09:19 Athletes Recovery and VO2 Max

13:52 Does NAD Decline With Age

20:10 Skin NAD and UV Damage

23:40 Who Should Take NR

27:56 Niacin vs NR vs NMN

32:28 NMN Conversion and Quality

35:37 IV and Injection Warnings

42:18 Dosing Timing and Alcohol

46:50 Addiction Claims and Dream Trials

51:39 Parkinsons and Long COVID Data

55:03 Sinclair Critique Revisited

57:05 Stacking Supplements and Metformin

59:58 Wrap Up and Where to Follow

The Hart2Heart podcast is hosted by family physician Dr. Michael Hart, who is dedicated to cutting through the noise and uncovering the most effective strategies for optimizing health, longevity, and peak performance.

This podcast dives deep into evidence-based approaches to hormone balance, peptides, sleep optimization, nutrition, psychedelics, supplements, exercise protocols, leveraging sunlight, and de-prescribing pharmaceuticals — using medications only when absolutely necessary.

Beyond health science, we explore the intersection of public health and politics, exposing how policy decisions shape our health landscape and what actionable steps people can take to reclaim control over their well-being.

Guests range from out-of-the-box thinking physicians such as Dr. Casey Means (author of "Good Energy") and Dr. Roger Sehult (Medcram lectures) to public health experts such as Dr. Jay Bhattacharya (Director of the National Institutes of Health (NIH) and Dr. Marty Mckary

(Commissioner of the Food and Drug Administration (FDA) and high-profile names such as

Zuby and Mark Sisson (Primal Blueprint and Primal Kitchen).

If you're ready to take control of your health and performance, this podcast is for you.We cut through the jargon and deliver practical, no-BS advice that you can implement in your daily life, empowering you to make positive changes for your well-being.

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