Saturday, November 5, 2011

Astragalus membranaceus: Purported Telomerase Activator Increases Exercise Capacity by +56%, Fights Cancer and May Be a Healthy Adjunct to Chemotherapy and Vaccines

Image 1: Astragalus membranaceus, one of the 50 fundamental herbs in traditional Chinese medicine (TCM). A purported telomerase activator that contains potent antioxidants.
There is hardly one month passing without some media reports about a group of scientists who supposedly found the royal route to health and longevity. With all those potentially life-extending drugs, herbals and nutritional supplements that have thus surfaced in the course of the last decades, it is actually almost surprising that we still die like flies, isn't it? Well, one possibility would obviously be that the scientifically-backed wonder-potions you can buy in the snake-oil shops all over the Internet do not work at all - impossible? I don't think so. Consequently, I was and still am very skeptical about the dubious claims about the "life-extending" effects of a patented Astragalus membranaceus (also Astragalus propinquus) extract - and that despite or, I should say, because of its "scientifically proven" effect on telomerase length in 114 older (63 +/-12 years) subjects. After all, the respective study was not only by the owner of the company which holds the patent for T-65(R), a (I quote) ">95% pure single chemical entity isolated from a proprietary extract of the dried root of Astragalus membranaceus" (Harley. 2011), but the authors (guess what all somehow involved in the sale of the product) also use several more or less clever tricks to polish their results. While they have to admit that
Two independent measures of median or mean telomere length (by FlowFISH and qPCR) showed no consistent change with time on PattonProtocol-1 (data not shown).
they cleverly handpicked 7 out of 13 tested subjects in which the percentage of nuclei with short telomeres had declined at 12-18 months compared to baseline. Now, while this decline may be statistically significant (p<0.05, according to the scientists), I wonder what happened to the other 6 subjects... and even if you were among those lucky 7, this does by no means indicate that that will actually prolong your life.

Who wants to live forever, anyway...

That I did nevertheless dig a little deeper into the research on astragalus had two reasons. One was that I wanted to find any other data on its potential effects on telomerase length - and more importantly its practical outcome in rodents or even my "favorite" subject of medical research, the roundworm Caenorhabditis elegans, or "C. elegans" (do I have to say that there are no such studies?). The other reason was that astragalus membranaceus has been used in Traditional Chinese Medicine for centuries. So, even if it would not make you live forever there obviously had to be some benefits to this flowering plant from the family of Fabaceae. And as it turned out, Chinese researchers have been performing numerous studies into its antioxidant, anti-diabetic, anti-hypertensive, and immunomodulatory activity within the last decades, of which a very recent one could be of particular interest for fitness enthusiasts and even professional athletes.

... isn't performance the only thing that counts?

Image 2: While this is not the exact model that has been used in the study, this is what "exercise" looks like if you are one of those poor lab rats... well, not so much different from what a whole host of trainers still suggest their clients should do to lose weight... but I am digressing, here ;-)
If you look at the sales-ranks of various dietary supplements, it is quite obvious that (potential) long-term effects on health and longevity usually stand second to immediate benefits like increased energy, well being, weight loss or exercise performance. "If you don't feel it, it doesn't work!" is the mantra of many fitness enthusiasts; a montra on which the manufacturers of purported fat-burners and pre-workouts, 99% of which are only caffeine, geranamine and yohimbine loaden stimulants, monetize big time. And as long as those cheap stims keep the sales of their products up, the producers obviously would be stupid if they changed their formulas and included more expensive "adaptogens" - chances are the customers would not be willing to pay the price, anyway. Accordingly, you won't find references to studies like the one Deng and Hu recently published in the Academic Journals on any of the labels of the currently available mainstream supplements (Deng. 2011).

In what they themselves claim is one of the few studies (to my mind the first to be published in an international journal) investigating the effects of Astragalus membranaceus polysaccharides (AMP) on exercise performance, the scientists from the Kunming University in China orally administered 50, 100 or 200mg/kg of previously extracted pure astragalus polysaccharides to 6-8 week old male Sprague-Dawley rats for 30 successive days. In the course of the last week of the experimental period the rats, who had been fed ad-libitum for the whole study period, were accustomed to running on a treadmill for 15-20min at 15-30 m/min (=0.9-1.8km/h), so that they would be able to perform an exercise test that consisted of running on a 10° incline (30m/min, ~75%VO2Max) until exhaustion on day 30.
Figure 1: Running time to exhaustion (in s, left) in rats who received either saline control or astragalus membranaceus polysaccharides at a dosage of 50, 100 or 200mg /kg per day and the extrapolated dose-response relationship (data calculated based on Deng. 2011)
As the data in figure 1 shows, the supplemental regimen, which had no effects on the body weight of the then 12-week old rats, significantly improved the running endurance of the laboratory animals. Interestingly, the extrapolation of the dose-dependency suggests that dosages above 300mg/kg (human equivalent ~50mg/kg) will probably not yield much better results than the 200mg/kg maximal dose that was used in the study (human equivalent ~35mg/kg).
Figure 2: Effects of astragalus supplementation on anti-oxidant enzymes after exhaustive endurance training in rats; values expressed relative to unsupplemented control (data calculated based on Deng. 2011)
The post-exercise glutathione peroxidase (GSH-Px) activity exhibits a similarly logarithmic dose-response relation (cf. figure 2). The decreases in malondyaldehyde (MDA), as well as the increase in superoxide dismutase (SOD), on the other hand appear to be almost linear. And, lastly, the lower increase in catalase (CAT) in the high dose astragalus group could be a consequence of the fact that, with GPH-Px and CAT both being responsible for the catalyzation of hydrogen peroxide to water, there simply was no need for additional cat activity, when the GPH-Px activity already increased by >100%.

If (the big if ;-) those results could be confirmed in human trials, the +56% increase in exercise endurance in the 200mg/kg (i.e. 35mg/kg for humans) of astragalus could in fact be the "next big thing" in terms of natural ergogenics. For the time being, it is yet only another item on the list of purported benefits, I am now going to conclude on another anon more health related note.

Beyond exercise performance: Cancer protection and immuno-modulation

While I initially voiced some doubts with regard to the purported longevity effects of astragalus, its relatively well-established anti-carcinogenic effects could well help many of us to substantially prolong our lives. After all, numerous studies have established the anti-cancerous activity of various natural constitutents of astragalus. Among the cancer cell lines that were tested were  
If you look a the publication dates and authors, you will notice that despite its longstanding tradition within TCM scientists have only lately begun to realize that we could have overlooked a vital contribution in the ongoing battle against cancer - and what's more, the studies are mostly done by TCM practitioners at the School of Chinese Medicine, who certainly ain't under suspicion to be interested in monetizing on a new drug. After all, natural medicine is not patentable.

From the petri dish to the bedside: APS improved quality of life in cancer patients.

Image 3: Astragalus has already proven its usefulness as an adjunct to the toxic cocktail cancer patients receive as part of their chemotherapy
In a first trial (Guo. 2011), the intravenous administration of astragalus polysaccharides (APS) at 250mg/day in connection with chemotherapy for 7 days lead to statistically significant improvements in the overall quality of life of advanced non-small-cell lung cancer patients. Personally, I find it most remarkable that it reduced the chemotherapy induced fatigue by >50% (as measured by a standardized Quality Of Life questionnaire). The objective response rate to chemotherapy was higher, as well: 42.64% (29/68) in the APS supplemented patients vs. 36.76% (25/68) in the control arm of the study, but these effects did not reach statistical significance (P = 0.483, indicating that chances are about 43% that this was just "conincidence").

In view of the immune-weakening effects of chemotherapy, it may also be important that astragalus has established anti-viral effects. It has been tested as an adjunct to interferon alpha-2b in anti-herpes therapy (Zhang. 1998) and against (chronic) hepatitis B infections (Wu. 2001; Dang. 2009) - the effects are yet rather mediocre and may be mediated by the same general immune-stimulatory effects of the herb (Block. 2003; Jiang. 2010). In this context, it is particularly noteworthy that a paper on herbal medicinces for viral myocarditis published in the reputable Cocraine Database of Systematic Reviews that ...
[..a]stragalus membranaceus (either as an injection or granules) showed significant positive effects in symptom improvement, normalisation of electrocardiogram results, CPK levels, and cardiac function.
And with the current vaccination-hysteria, we may soon see the practical realization of a proposal that has been made by Lin et al. in a recent paper on the effects of Astragalus polysaccharides (APS) on foot-and-mouth disease in swine (Lin. 2010), i.e. the addition of APS as an immuno-modulator for various vaccines (I guess it would certainly be better than mercury, don't you think ;-).

Conclusion: A promising herb... without a future?

Image 4: If all the info got you interested, Carl Lanore from Super Human Radio has recently sourced a bulk powdered version of astragalus. The bulk source is probably the only way not to run out of money before you notice any effects ;-)
Despite the accumulating evidence for the many health benefits that could be derived from the administration of crude extracts or isolated fractions of astragalus, chances that it will make it from Carl Lenore's Super Human Radio shop to the mass market are low ... or I should say non-existent, as long as the latter is still controlled by BigPharma and their right-hand men and women in the bureaucracy. After all, Astragalus membranaceus is not only non-patentable, it also does not appear to have any side-effects, the pharma companies could monetize on ;-) So regardless of whether future studies will validate or maybe falsify the hopes many naturopaths and TCM practitioners are pinning on this herb, MDs who follow the official guidelines, which state that the...
evidence for using astragalus for any health condition is limited. High-quality clinical trials (studies in people) are generally lacking (NCCAM. 2010),
will probably never prescribe it to their patients... unless, well unless some genius of a molecular biologist in one of the pharma-companies applies a few minor melcular tweaks to some of the active ingredients of astragalus, so that his company can file a patent application that goes beyond the extraction technique that has been patented for Harley's (questionable) T-65(R).