Tag: NAD+

Boosting NAD+ levels to slow down the aging processes might be the biggest “biohack” project emerging on the horizon.  Most importantly, in the context of anti-aging, NAD+ (Nicotinamide adenine dinucleotide) activates sirtuins.  What are sirtuins? They are signaling proteins that take care of essential functions in our body including DNA repair and other housekeeping functions, for instance, maintaining our hair and fertility.  Sirtuins are also involved in protecting us from age-related diseases such as Alzheimer’s disease and heart failure.  For Sirtuins to work properly, sustaining adequate levels of NAD+ is essential.  How are NAD+ levels and Sirtuin activities associated? Unfortunately, NAD+ levels decline as we age (Figure 5):    For Sirtuins to work properly, sustaining adequate levels of NAD+ is essential.  However, with this decline in NAD+, sirtuin activities cannot be sustained and age-related diseases escalate.  Can we delay aging by boosting NAD+ levels? The bold hypothesis that we could delay aging processes by boosting NAD+ was proposed by renowned scientists such as David Sinclair at Harvard Medical school.  Successful animal studies of that hypothesis have been published in well-established journals Nature, Science, and Cell.  Boosting NAD+ levels could be the spring that leads us to the fountain of youth. 

NAD+ is a bulky molecule that is not absorbed orally and needs to be given intravenously.  Intravenous administration can be inconvenient and costly.  On the other hand, two key NAD+ precursors (see Figure 7), NMN (Nicotinamide Mononucleotide) and NR (Nicotinmaide Riboside), are smaller and cheaper than NAD+, and can be taken orally.  Unlike NAD+ whose scientific data in the context of longevity is lacking, NMN and NR have been extensively investigated in various settings including in animals and sometimes in humans.  Two important questions come up: 1) Will taking NMN or NR boost NAD+ levels in our body and 2) provide the benefits of NAD+?      Question 1: The first question is whether taking NMN and NR increases NAD+ levels?  It appears so as evidence listed below shows.  NMN NMN administration effectively enhances NAD+ levels in various peripheral tissues: Pancreas (Yoshino et al., 2011) Liver (Peet et al., 2013, Yoshino et al., 2011) Adipose tissue (Stormsdorfer et al., 2016, Yoshino et al., 2011) Heart ( Karamanlidis et al., 2013, Martin et al., 2017, North et al., 2014, Yamanmoto et al., 2014) Skeletal muscle ( Gomes et al., 2013) Kidney (Guan et al., 2017)Testis (North et al., 2014) Eyes (Lin et al., 2016) Blood vessel  (de Picciotto et al., 2016).  NR NR has shown to increase NAD+ levels in multiple tissues and in blood in both mice and humans.  In a study conducted in 2017, a dose of 250mg NR plus polyphenol 50mg increased blood NAD+ levels by 40% (see Figure 8 below).  A dose of 500mg NR plus polyphenol 100mg increased blood NAD+ levels by 90%.  Figure 8: NAD+ level as a result of NR intake.  Figure borrowed from Dellinger, R.W., Santos, S.R., Morris, M. et al. Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD+ levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study. npj Aging Mech Dis 3, 17 (2017). Question 2: The second question is whether taking NMN and NR show benefits associated with elevated NAD+ levels.   Therapeutic benefits of NMN shown in mice, consistent with elevated NAD+ levels, can be summarized as follows: Improvement in insulin secretion and insulin sensitivity- Revolio et al., 2007 and  Ramsey et al., 2008, Yoshino et al., 2011, Caton et al., 2011, Stromsdorfer et al., 2016, Mills et al., 2016 Improved skeletal muscle function – Gomes et al., 2013 Improved neural function – Stein and Imai, 2014, Park et al., 2016 Improved mitochondrial function – Long et al., 2015 , Mills et al., 2016 Improved cardiac function – de Picciotto et al., 2016, Lee et al., 2016 Protected from retina injury – Lin et al., 2016, Stromsdorfer et al., 2016 Improved cognitive function – Wang et al., 2016, Yao et al., 2017 Protected kidneys from chemotherapy – Guan et al., 2017 Therapeutic benefits of NR shown in mice, consistent with elevated NAD+ levels, are as follows: Improved insulin sensitivity – Canto et al., 2012 Improved cognitive function – Gong et al., 2013 Improved muscle endurance and function – Cerutti et al., 2014, Frederick et al., 2016, Ryu et al., 2016, Elhassan et al., 2019 Protection against tumor growth in livers – Tummala et al., 2014 Lowered cholesterol –  Lee et al., 2015 Protected against neural pain – Trammell et al., 2016 Increased lifespan – Zhang et al., 2016, Fang et al., 2016 Improved motor coordination – Fang et al., 2016

Top selling NMN products on Amazon do not necessarily have the NMN potency that they claim on their labels.  Shockingly, only 3 of the 22 products that were recently tested by ChromaDex, an independent company, had NMN content at or above the labeled amount.  To find the “best NMN supplement,” consumers need to take a more analytical approach, rather than following claims made by top-selling manufacturers.   Shockingly, 14 out of 22 supplement brands contain virtually no NMN: NMN and NR are considered dietary supplements, and the Food and Drug Administration (FDA) does not regulate the manufacturing processes of supplements, quality control is a critical factor consumers need to consider.  The quality control issue came under scrutiny when ChromaDex, a company that makes NR, tested and published in October 2021 the purity of 22 NMN products with the highest market share on Amazon.  ChromaDex received those samples on September 8, 2021 and analyzed them by conducting High Performance Liquid Chromatography (HPLC) tests using a UV-Vis detector.  The results are tabulated below: This data was shocking because 14 of the 22 brands had below reporting limit (BRL) or not detected (ND) results, i.e. less than 1% of the claimed NMN content. Which brands are acceptable? 5 of the 22 had NMN content “just below label claim,” in the 88-99% range.  Only 3 of the 22 brands had content at or above the label claim.  Those three top brands are       Infinite Age NMN Macc10 NMN ProHealth Longevity NMN Some manufacturers are now responding to consumers’ quality concerns by self-reporting third-party conducted analyses of their own products.  For example, ProHealth Longevity hired Micro Quality Labs, Inc. in Burbank, California, to test its product and displayed its results on Amazon.  Another manufacturer, Renue By Science (formerly known as Alive By Science), also used Micro Quality Labs to test and show that their products are at least 98% “pure.”  Since manufacturers are continuously self-reporting updated third-party tests, consumers should look for those updates. Can you run supplement quality tests on your own? Consumers themselves can choose to hire a third-party analytical lab to test a product.  While many analytical labs might not entertain the idea of working with individual clients, some labs like Summit National Laboratories in Utah charge approximately $200.00 to analyze samples for any clients.  The analytical labs request that you send them about 20 – 25 grams of the samples of your interest.       Go with products with high purity In conclusion, any of the top brands listed below that reported at least 98-99% purity in their products appear to be a sensible choice: Infinite Age NMN Macc10 NMN ProHealth Longevity NMN Renue By Science NMN

Should you take NMN or NR?  While one group of scientists including Charles Brenner at University of Iowa focuses on NR, another group of scientists including David Sinclair at Harvard focuses on NMN as the NAD+ supplement.  We need to examine the pros and cons of taking NR vs. NMN.      Arguments for NR: One of the primary reasons earlier scientists used NR to study the effects of NAD+ was that NR is cheaper than NMN.  NMN, which is a step closer than NR to NAD+, the final product (See Figure 9), is more expensive to synthesize because of its additional phosphate group.  Another reason some scientists like to use NR, instead of NMN, is because they believe that NMN might be too bulky to be taken into cells whereas the smaller NR can easily enter cells.     Arguments for NMN: Despite NMN’s bulkier size than NR, the recent discovery of an NMN-specific transporter completely changes the story; NMN-specific transporter Slc12a8 was identified in mice, proving that NMN can be effectively taken into cells at least in mice.  The Slc12a8 gene is present in humans too and could play a critical role in transporting NMN into human cells.  However, more studies need to be conducted in humans.   At the same time, NMN might be more effective in boosting NAD+ levels than NR because NMN has its own phosphate group, which is not abundant in the body. So, NR or NMN? Between NMN and NR, there is no strong evidence at this point to support one molecule over the other.  David Sinclair, however, states in his “Lifespan with Dr. David Sinclair’ podcast episode #4 aired on January 26, 2022,  that he uses NMN because he personally saw more favorable outcomes with NMN than NR. 

Benefits of NAD+ (by taking NMN or NA supplements; NMN and NA will be further discussed) has been shown in animal studies to improve the lifespan and healthspan by–but not limited to– the mechanisms as summarized in figure 5.  NAD+ can improve our nervous system, improve liver function, improve blood flow, protect against age-related diseases, lower inflammation, and even improve fertility.   Improving and Preserving Neuronal Function NMN and NR treatments can improve cognition, motor function, and preserve neuronal functions, and sometimes reverse, neuronal damages. For more information, see references below: Park, J.H., Long, A., Owens, K., and Kristian, T. (2016). Nicotinamide mononucleotide inhibits post-ischemic NAD(+) degradation and dramatically ameliorates brain damage following global cerebral ischemia. Neurobiol. Dis. 95, 102–110. Wei, C.C., Kong, Y.Y., Li, G.Q., Guan, Y.F., Wang, P., and Miao, C.Y. (2017b). Nicotinamide mononucleotide attenuates brain injury after intracerebral hemorrhage by activating Nrf2/HO-1 signaling pathway. Sci. Rep. 7, 717. Gong, B., Pan, Y., Vempati, P., Zhao, W., Knable, L., Ho, L., Wang, J., Sastre, M., Ono, K., Sauve, A.A., and Pasinetti, G.M. (2013). Nicotinamide riboside restores cognition through an upregulation of proliferator-activated receptor-g coactivator 1a regulated b-secretase 1 degradation and mitochondrial gene expression in Alzheimer’s mouse models. Neurobiol. Aging 34, 1581–1588. Hou, Y., Lautrup, S., Cordonnier, S., Wang, Y., Croteau, D.L., Zavala, E., Zhang, Y., Moritoh, K., O’Connell, J.F., Baptiste, B.A., et al. (2018). NAD+supplementation normalizes key Alzheimer’s features and DNA damage responses in a new AD mouse model with introduced DNA repair deficiency. Proc. Natl. Acad. Sci. USA. Published online February 5, 2018. Long, A.N., Owens, K., Schlappal, A.E., Kristian, T., Fishman, P.S., and Schuh, R.A. (2015). Effect of nicotinamide mononucleotide on brain mitochondrial respiratory deficits in an Alzheimer’s disease-relevant murine model. BMC Neurol. 15, 19. Sorrentino, V., Romani, M., Mouchiroud, L., Beck, J.S., Zhang, H., D’Amico, D., Moullan, N., Potenza, F., Schmid, A.W., Rietsch, S., et al. (2017). Enhancing mitochondrial proteostasis reduces amyloid-b proteotoxicity. Nature 552, 187–193. Wang, X., Hu, X., Yang, Y., Takata, T., and Sakurai, T. (2016). Nicotinamide mononucleotide protects against b-amyloid oligomer-induced cognitive impairment and neuronal death. Brain Res. 1643, 1–9. Fang, E.F., Scheibye-Knudsen, M., Brace, L.E., Kassahun, H., SenGupta, T., Nilsen, H., Mitchell, J.R., Croteau, D.L., and Bohr, V.A. (2014). Defective mitophagy in XPA via PARP-1 hyperactivation and NAD(+)/SIRT1 reduction. Cell 157, 882–896. Brown, K.D., Maqsood, S., Huang, J.Y., Pan, Y., Harkcom, W., Li, W., Sauve, A., Verdin, E., and Jaffrey, S.R. (2014). Activation of SIRT3 by the NAD+ precursor nicotinamide riboside protects from noise-induced hearing loss. Cell Metab. 20, 1059–1068. Dutca, L.M., Stasheff, S.F., Hedberg-Buenz, A., Rudd, D.S., Batra, N., Blodi, F.R., Yorek, M.S., Yin, T., Shankar, M., Herlein, J.A., et al. (2014). Early detection of subclinical visual damage after blast-mediated TBI enables prevention of chronic visual deficit by treatment with P7C3-S243. Invest. Ophthalmol. Vis. Sci. 55, 8330–8341. Hamity, M.V., White, S.R., Walder, R.Y., Schmidt, M.S., Brenner, C., and Hammond, D.L. (2017). Nicotinamide riboside, a form of vitamin B3 and NAD+ precursor, relieves the nociceptive and aversive dimensions of paclitaxel-induced peripheral neuropathy in female rats. Pain 158, 962–972. Lin, J.B., Kubota, S., Ban, N., Yoshida, M., Santeford, A., Sene, A., Nakamura, R., Zapata, N., Kubota, M., Tsubota, K., et al. (2016). NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice. Cell Rep. 17, 69–85. Vaur, P., Brugg, B., Mericskay, M., Li, Z., Schmidt, M.S., Vivien, D., Orset, C., Jacotot, E., Brenner, C., and Duplus, E. (2017). Nicotinamide riboside, a form of vitamin B3, protects against excitotoxicity-induced axonal degeneration. FASEB J. 31, 5440–5452. Yin, T.C., Britt, J.K., De Jesu´ s-Corte´ s, H., Lu, Y., Genova, R.M., Khan, M.Z., Voorhees, J.R., Shao, J., Katzman, A.C., Huntington, P.J., et al. (2014). P7C3 neuroprotective chemicals block axonal degeneration and preserve function after traumatic brain injury. Cell Rep. 8, 1731–1740. Zhuo, L., Fu, B., Bai, X., Zhang, B., Wu, L., Cui, J., Cui, S., Wei, R., Chen, X., and Cai, G. (2011). NAD blocks high glucose induced mesangial hypertrophy via activation of the sirtuins-AMPK-mTOR pathway. Cell. Physiol. Biochem. 27, 681–690. Improving Liver Function NAD+ protects the liver from fat accumulation, hepatitis, high LDL cholesterol levels, and insulin resistance. For more information, see references below: Mukherjee, S., Chellappa, K., Moffitt, A., Ndungu, J., Dellinger, R.W., Davis, J.G., Agarwal, B., and Baur, J.A. (2017). Nicotinamide adenine dinucleotide biosynthesis promotes liver regeneration. Hepatology 65, 616–630. Gariani, K., Ryu, D., Menzies, K.J., Yi, H.S., Stein, S., Zhang, H., Perino, A., Lemos, V., Katsyuba, E., Jha, P., et al. (2017). Inhibiting poly ADP-ribosylation increases fatty acid oxidation and protects against fatty liver disease. J. Hepatol. 66, 132–141. Altschul, R., Hoffer, A., and Stephen, J.D. (1955). Influence of nicotinic acid on serum cholesterol in man. Arch. Biochem. Biophys. 54, 558–559. Garg, A., Sharma, A., Krishnamoorthy, P., Garg, J., Virmani, D., Sharma, T., Stefanini, G., Kostis, J.B., Mukherjee, D., and Sikorskaya, E. (2017). Role of Niacin in current clinical practice: a systematic review. Am. J. Med. 130, 173–187. Rivin, A.U. (1962). Hypercholesterolemia. Use of niacin and niacin combinations in therapy. Calif. Med. 96, 267–269. Gariani, K., Menzies, K.J., Ryu, D., Wegner, C.J., Wang, X., Ropelle, E.R., Moullan, N., Zhang, H., Perino, A., Lemos, V., et al. (2016). Eliciting the mitochondrial unfolded protein response by nicotinamide adenine dinucleotide repletion reverses fatty liver disease in mice. Hepatology 63, 1190–1204. Protecting Blood Flow Function NAD supplementation is a potential approach to increase mobility in the aged-population that suffer from slow wound healing and muscle pain as a result of decreased blood flow. Old mice treated with NMN improved blood flow and endurance.  See below for references: de Picciotto, N.E., Gano, L.B., Johnson, L.C., Martens, C.R., Sindler, A.L., Mills, K.F., Imai, S., and Seals, D.R. (2016). Nicotinamide mononucleotide supplementation reverses vascular dysfunction and oxidative stress with aging in mice. Aging Cell 15, 522–530. Rajman et al., “Therapeutic Potential of NAD-Boosting Molecules: The In Vivo Evidence,” Cell Metabolism 27, March 6, 2018, pg.529 -547 Protecting Heart Function Adequate NAD+ levels are essential for recovery of age-related heart diseases. See below for references: Ryu, D., Zhang, H., Ropelle, E.R.,