X-Message-Number: 22450 From: "michaelprice" <> References: <> Subject: NAD & Sir Date: Mon, 1 Sep 2003 11:42:11 +0100 Doug Skrecky wrote: >> NAD (the coenzyme form of vitamin B3) is a >> substrate for sirtuins, which consequently >> up-regulates sirtuin activity. >> > I'm told it does not. Perhaps you're thinking of PMID: 12297502 ? This subject has been extensively knocked about on sci.life-extension, where it continually resurfaces every few months. I advise anyone who wishes to investigate in depth to google on the sci.life-extension archives using the PubMed indices I've given in this post. I'm surprised that Doug, as a committed life-extensionist, doesn't make more use of the sci.life-extension newsgroup himself. > NAD is not a limiting factor for Silent Information > Regulator activity under normal circumstances. Not according to PMID: 11884393, and I quote: "This finding suggests that yeast life span extension may be facilitated by an increase in the availability of NAD(+) to Sir2, " > Nicotinamide can reduce SIR activity by > blocking the NAD site, Correct. As we would expect since nicotinamide is a product, not a substrate, of SIR. > but niacin has no effect. Wrong. Extra oral niacin, over and above RDA levels, typically increases intracellular NAD levels by a factor of 2 or 3 and, in mammals, lowering the incidence of cancer by >40% (PMIDs 6213941, 11773517, 10453439) and reduced human long-term mortality (PMID: 3782631). Cheers, Michael C Price http://mcp.longevity-report.com http://www.hedweb.com/manworld.htm Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=22450