Astragalus vs. Astragaloside IV, which is better for kidney health?
Of recent Astragalus extracts have become particularly popular in the bodybuilding community with the goal to improve kidney health. The efficacy of this notion has long been questioned in our team at Strom due to variable outcomes in blood testing. However I think an evidence based answer can be provided. This is what the following discussion aims to achieve.
Astragaloside IV appears to be a viable compound to improving kidney health in models and animal trials, but NOT supplementing with whole Astragalus extracts without demonstrated Astragaloside IV content.
Considering non-standardised Astragalus extracts is the bulk of what you will see in the industry, this is not a statement we make lightly… especially given a number of the “leading evidence based” brands which still continue to manufacture inadequate kidney health supplements.
First to address the efficacy of Astragaloside IV.
Does Astragaloside IV
improve kidney health
in humans?
As of February 2024, there doesn’t appear to be any human clinical trials investigating the standalone compound Astragaloside IV. This should frame the entire discussion going forward.
What we do have is an abundance of animal and cell culture research showing indications for anti-inflammatory activities that is protective - not only for kidney tissue, but also brain, liver and more.
Research showing Astragalus and other Astragaloside IV combinations improve kidney function is also available, however we need to be careful about what results we view as valid.
Why don’t whole
Astragalus extracts
reliably improve
kidney health?
Simply put, non-standardised Astragalus extracts do not reliably contain any detectable Astragaloside IV, and currently we do not have reason to believe Astragalus has significant kidney health promoting effects without Astragaloside IV.
According to multiple studies testing Astragalus supplements currently on the market, less than a quarter of those tested had detectable Astragaloside IV present. But in those with detected quantities, the concentration present was so low that reaching an efficacious dose would not be practical.
The highest concentration astragalus extract contained 0.14% Astragaloside IV.
Currently accepted dosing of Astragaloside IV in humans is in the range of 5 - 50mg.
Hence in order to reach the low dose of 5mg Astragaloside IV: 3.6 grams of that Astragalus extract would need to be consumed daily. To emphasis, that is not whole root equivalence, but rather final extracted product. That's about 6 capsules just for the lowest dose and the highest performing extract!
To obtain a stronger, more efficacious dose of 25mg - like that in the Leviathan Kidney Support, it would require 18g of the same extract. Think ~30 capsules daily.
But I heard Astragalus
decreases creatinine, and
creatinine derived eGFR?
Yes it does, but important to acknowledge is that creatinine and eGFR derived from creatinine concentrations are not an absolute proof of kidney health, only one test used as an indicator.
While it can be useful in normal populations to provide a warning for kidney health at very low cost, it is not a direct measure of kidney health and is highly variable, making it often misleading.
However there is another blood test marker available for testing to indicate rate of kidney filtration. That is Cystatin C.
Cystatin C is a more reliable marker due to being less susceptible to variability. If the trend of these two markers are compared, in a case of truly improved kidney function they should follow the same curve.
In human research regarding whole Astragalus extracts, creatinine levels are often lowered, but many papers do not investigate Cystatin C. Those that do investigate Cystatin C show no decrease.
Hence indicating that compounds within astragalus are decreasing the detectable creatinine in circulation, which does not in itself improve kidney health, but is rather masking what would otherwise indicate poor kidney health. If kidney health was truly improved, Cystatin C should also decrease proportionally with how much creatinine decreased.
How does Astragalus decrease
tested creatinine concentration
without improving
kidney filtration rate?
This is not currently known. However there are some known pathways that can increase creatinine clearance separate to kidney health. One of which is by altering transporter activity in the kidney, which may actively “pump” creatinine out of circulation, to be excreted in urine.
So what Astragalus
supplementation
would we recommend?
Right at this moment, the best approach Astragalus supplementation would appear to be using the synthetic Astragaloside IV compound. There are also a number of herbal Astragalus products on the market claiming to be high concentrations of Astragaloside IV. I would heed more caution with these, but not discount them entirely.
Of what we stock in store, our top recommendation is the Leviathan Kidney Support product which utilises 25mg of synthetic Astragaloside IV.
You have been informed of our position, now it’s time for you to decide for yourself. Any contra indications would be very welcomed.
- Thomas, Strom Downunder
Further Reading
Pharmacological Effects of Astragaloside IV: A Review (July 2023)
— — —
05.03.2024 -This article was originally published at stromsports.co.nz
FOUND THIS HELPFUL?
This content is for educational purposes only and does not intend to cure or diagnose disease, nor make any health claims. There is no intent to slander in any way, but rather produce an informed and accurate third party perspective on the product. Always consult your accredited medical professional before introducing a new supplement. This content is not to be copied or repurposed in any form without express permission from the author.