How long does it take for the effect to kick in - if I do CR for a week and then start eating normally and taking ALA, what will happen? Or what if I stop taking ALA and start doing CR?
cool. So i do CR for 6 months withoutout ALA and then eat the next 140 years as much as i want with ALA xD
So those of us who have taken lipoic acid without CR are doomed; CR will not help now.
It's good to see people asking the right questions ...
First, please read my
disclosure here; in particular: while there, it was my initiative that sourced, brought to market, and promoted the first R(+) lipoic acid supplement on the market (ie, the physiological enantiomer, rather than the "alpha-lipoic acid" racemate in most supplements and used as a diabetes drug in Europe). This was rapidly followed up by a lot of companies producing fraudulent and/or poor-quality knock-off products, many of them plagiarizing my writing or nakedly cribbing from it to add literary insult to material injury. The big exception was of course Geronova, who were real pioneers in a way that even my company was not, producing new science and developing a potassium salt whose superior stability & bioavailability they have actually documented, including an human bioavailability study (1). (Altern Med Rev has historically been mostly a disguised infomercial for a supplement company, and IMO certainly should not be MEDLINE-indexed without a great deal of reform, but note Lester Packer's involvement; as well, Geronova's driving force, David Carlson, and am convinced of his sincerity & competence). (FWIW, my old employer, in addition to having the regular stuff, produces a tromethamine salt which (at least when formulated by the former Asta Medica (now part of Swedish pharmaceutical company Meda AB)) has also
shown superior bioavailability).
Next, please indulge me in a bit of preamble. As most of you know, Tory Hagen and Bruce Ames did some extremely exciting work around the turn of the century, showing late-life 'rejuvenation' of heart and brain with the R(+) form of lipoic acid, which encouraged a lot of people to think that it might actually slow down biological aging; this was encouraged further by the mechanistic hypothesis that, by lowering electron reduction at Complex I, R(+)-lipoic acid might actually reduce the mitochondrial
generation* of free radicals (rather than merely quenching some of them as an antioxidant
post facto).
Unfortunately, lipoic acid has consistentently failed to extent lifespan in rodent studies. As part of the
LEF LifeSpan Project, Steve Spindler tested the
racemate at 600 mg/kilogram of the control diet -- either or with NAC (2000 mg/kg), vitamin E (585 mg/kg), and lycopene (300 mg/kg) and found no effect (2); under the same funding source, racemic lipoic acid (600 mg/kg) also flunked for Weindruch; and even R(+) flunked for Ames (personal communication to me & several others at SENS1 -- he's never published it, alas).
However, several researchers -- Spindler (2), Weindruch, Ames (who offered this as an explanation for the R(+) flunk), and de Grey -- have noted that well-cared-for, longevous mice die so overwhelmingly of cancer (having not fallen prey to anything else first) that an intervention that had strong impacts on multiple mechanisms of aging but that did not
directly impact cancer might have no detectable impact on lifespan. CR, in this model, might have at least 2 major effects that combine to delay death: retardation of aging
per se, and an antiproliferative effect which (in
combination with the reduction of the age-associated increase in vulnerability to mortality) prevents the animals from dying early from cancer. Clearly, CR is not
just a cancer therapy -- but such a bimodal effect might help to explain the discordant effects on the survival curve in mice (shift the curve to the right) vs rats (pull out the curve).
Creative genius that he is, de Grey has come up with an experimental design that would help to resolve this question: do the experiment in cancer resistant (albeit short-lived) mutant mice with unusually active p53 (4,5). While still potentially susceptible to confounding from effects of high p53 activity on tissue renewal, this might allow the anti-aging effect of any particular intervention to be isolated from any anticancer effect.
Of course, if this hypothesis is correct, then done and dusted interventions suddenly spring forth from the soil: we open up an enormous panoply of antioxidant and other interventions which suddenly once again become plausible anti-aging therapies. But R(+) strikes me as a particularly promising candidate for a couple of reasons.
First, although many of the antioxidant effects of lipoic acid have been shown to be due to Nrf2 stimulation rather than its intrinsic antioxidant properties or its metabolite, DHLA (6), it's still possible, mechanistically, that by lowering electron reduction at Complex I, lipoic acid actually lowers mtROS
generation; if, per MiFRA, mtROS fuel aging, this would fit the above model nicely, as of course mtROS overwhelmingly 'hit' mtDNA & virtually never DIRECTLY 'hit' nuDNA -- & in any case, mutations leading to cancer in the real world overwhelmingly do not come from ROS, but from errors in fidelity of DNA replication.
Second, the effects reported by Hagen and Ames for late-life 'rejuvenation' of heart and brain are pretty darned impressive AFAICS -- in some respects, better than those of CR.
And now comes this recent report by Brian Merry (who is one of my all-time favorite biogerontologists) (7).
CR folk of course have always wished someone would do good studies
combining promising-looking antioxidants and other putative anti-aging interventions with CR, which has essentially never been done except in one old study by Weindruch, Walford, and Harris (8) with the synthetic antioxidants ethoxyquin and 2-mercaptoethylamine and ethoxyquin ethoxyquin back in teh 80s; in that study, unfortunately, the CR animals' small livers apparently couldn't handle the stuff (ethoxyquin is hepatotoxic) -- a flop, but not particularly insightful.
Merry's group combined different combinations of age of onset and CR or AL (including switching from CR in early life with AL late, eg) with and without lipoic acid. Without going thru' the results in detail, most of the results of the various switches between CR and AL diets were as you would expect from previous studies in rats (as distinct from what you see in mice). It was principally the inclusion of lipoic acid (racemic, unfortunately) that made it interesting. Also unfortunately, most of the cohorts were somewhat too small (25 animals), which made the results underpowered. From personal correspondence with Merry, this was not
just lack of funding (tho' that played into it of course --
sigh ), but also because it was originally designed primarily to test the effects on redox sensitive transcription factors, which would be expected to change with age, CR, and lipoate status.
The results to hand have enough solid data, and enough room for speculation, to make for a very tantalizing read. Now, Merry was most intrigued by an apparent 'memory' effect highlighted in these popular articles: "Animals fed ad libitum alpha-lipoic acid supplemented diet 2–12 months, then switched to DR feeding the [unsupplemented] diet" decidedly did not do as well as animals switched from
unsupplemented AL to unsupplemented CR -- they seemed 'fixed' in their old life trajectory.Animals switched earlier (at 6 mo) and thus given more time on CR had an intermediate survival, mostly due to a more AL-like mortality pattern in midlife. Contrariwise, animals initially on CR, but switched to AL + LA at 12 months, seemed to do pretty nearly as well as animals kept on CR throughout life, and those switched a little earlier had survival intermediate between AL and CR. Merry's hypothesis is that the supplement exerts a stable, epigenetic effect on REDOX-sensitive transcription factors, and thus prevents the shift into the alternative metabolic state.
There is one major confounder to this study, which is that they nowhere indicate that the AL --> CR (± LA) @ 12 mo groups were
eased into CR. As previously discussed,
adult organisms must enter into CR gradually to get the LS benefits. So the 'memory' effect might simply reflect a CR protocol that wouldn't've worked anyway. However, there are several lines of evidence against this in the report. First, surprisingly (granted the equivalent
mouse data), the AL --->
unsupplemented CR @12 mo group
did enjoy a LS gain that looks like a straight dose-response CR effect. Perhaps this is a species-specific result: the survival curves of rats and mice on CR do have distinct profiles (9), tho' certainly no one has ever made 'shock therapy' work in still older rats (17 mo + -- (eg, (10,11)). IAC, the fact that it worked in Merry's hands in this report shows that the same protocol
absent the LA does give a classic anti-aging CR life extension effect, suggesting that the addition of LA really did somehow impair the shift into 'CR mode.' There is also the consistency of the cohort that made the switch at 6 mo (say, 17 human-equivalent years): CR initiated at this time this did extend life without the LA, and this result confirms previous findings that CR still works as 'shock therapy' in rats at this age (eg, 12). Yet, here, adding in LA impaired this benefit as compared to the same protocol without the supplement. It's interesting that this group had an
intermediate LS, better than lifelong AL (± LA) but not as good as AL ---> unsupplemented CR at the same, youthful age; note, especially, that that the survival curve shows typical AL mortality during AL and continuing for some months after the switch to the CR + LA diet, but that they did eventually enter into a more CR-like pattern (see Fig 4b), suggesting a memory effect that was overcome with enough time and initial youthful metabolic flexibility. And, finally, there is the corresponding CR ---> AL (± LA) data, which is again consistent with Merry's hypothesis.
IAC, while this is all very intriguing, it has no practical import for most individual life extensionists who gets started as adults:
How long does it take for the effect to kick in - if I do CR for a week and then start eating normally and taking ALA, what will happen? Or what if I stop taking ALA and start doing CR?
cool. So i do CR for 6 months withoutout ALA and then eat the next 140 years as much as i want with ALA xD
No. First, no one can 'do CR for a week': again, to work in adults (and no one is advocating its imposition on children!), you have to ease your way into CR
gradually[/url]. The process takes a month in rodents; this could be many months, or credibly even a few years, in humans. Second, these animals started on CR at weaning; it's far from clear that the same reprogramming or epigenetic effects would be observed in adults (more work for the Merry lab!). And third, 6 to 10 months in a rodent is a very long time indeed: the human equivalent of ~16 and ~27
years --not something you can crash in on briefly.
So those of us who have taken lipoic acid without CR are doomed; CR will not help now.
This worry is the converse of the overly-optimistic interpretation above; and yes, if you've been on high-dose LA on an AL diet for many years, I'd say this study definitely is a bummer. I sure hope you're a member of
The 300 . Ironically, in this case, many life extensionists will for once have benefitted from the misrepresentations of supplement companies: plenty of people out there life extensionists only take a couple of hundred mg -- far too little of the stuff to exert a meaningful physiological effect anyway
or only recently bumped up their dose. In my own case, I started on a mere 50 mg LA back in the early 90s, and while I was still eating AL was rarely over 150 mg until after I'd been on CR for a couple of years.
From my own perspective as an established CR practitioner, I was most interested in "Group 11": the rats that were put on CR, and then had LA
added, without switching back to AL eating. In particular, median, mean, and "max LS" (eyeballed single longest-lived animal from the survival curve -- not the proper, 10th decile survivorship operational definition, for which unfortunately they didn't provide numbers) were, in days:
Lifelong AL: 926 - 854 - 1100
Lifelong AL + lipoic: 900 - 858 - 1105
CR --> AL + LA @ 6 mo: 996 - ? - 1210
CR --> AL + LA @ 12 mo: 1041 - ? - 1205
Lifelong CR: 1047 - 1025 - 1210
CR, + Lipoic @ 12 mo: 1125 - 1068 - 1230
I've also attached the relevant survival curves. Again, the study is underpowered, but
looks as if there may have been a modest benefit for the combination -- particularly relatively late in life. If such an effect is real, IAC, it's very small. I think this consistent with the idea that CR both retarded 'aging' and inhibited tumors, and the lipoate boosted the former just a little bit, whereas there was no such benefit for AL as per the hypothesis under discussion. Unfortunately, the paper doesn't give any pathology results; I have asked Dr. Merry if he has any data on this, tho' I suspect that the low cohort numbers will make any results extremely uncertain.
Dosage: LA was administered at 0.15% of diet weight; per Merry's email to me, "The DR rats eat between 8.5 and 11.5 g of food per day depending on their age so this would be a consumption of 10-13 mg of LA per animal per 24 hours. So if we average this and say about 11 mg of lipoic acid per animal of about 200g" we get 55 mg/kg body weight.
Adjusting for Kleiber's law of metabolic scaling, this is 890 mg/d in what was, prior to the obesity epidemic, an average American adult of 70 kg; this is one of those cases where CR saves you some money
. These doses are in the ballpark, at least, of doses used in clinical trials and approved in Europe for use in diabetes, and also of the extrapolated doses from the Hagen/Ames studies.
The benefit, if any, of adding LA to CR is so minimal that I'm not sure it's worth running after; at the very least, it's reassuring that LA clearly didn't
hurt the CR animals, or impinge on their benefits. (Nothing stupider than spending 40 yrs weighing your food and being bored to tears by "CR may not make you live longer, but it'll sure feel that way" clichés in the pop press, only to have it undermined by a stupid
dietary supplement). OTOH, the Hagen/Ames results, and some people's subjective benefits, might make it worth while for CR people in late middle age to take it up at an appropriate dose.
-Michael
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Edited by Michael, 09 August 2008 - 08:19 PM.