Does Astragalus Have Benefits for Life Extension and Fighting Cancer?

In 2008, it was reported that a screening of traditional Chinese medicine plants identified a compound called cycloastragenol in the roots of the astragalus plant that appeared to moderately enhance telomerase activation. That’s an enzyme I’ve covered before that our body uses to try to reverse one aspect of cellular aging by elongating your telomeres, the protective caps on your chromosomes. Three years later, after it was shown to elongate short telomeres and improve healthspan (though not lifespan) in mice, a one-year human trial was published. Although in most of the subjects telomeres continued to shorten on average, there did seem to be a significant reduction in the proportion of cells with critically short telomeres. And the side effects looked good, including a drop in LDL cholesterol and blood pressure. But, there was no control group and cycloastragenol (branded as “TA-65”) was but one of over fifty vitamins, minerals, herbs, and other compounds they gave to the research subjects that year.

When TA-65 was finally properly put to the test in randomized controlled trials, there was no cholesterol or blood pressure benefit whatsoever, but in cytomegalovirus-positive patients, a significant telomere lengthening effect was demonstrated at one dose but not another. (Those with chronic viral infections, such as CMV or HIV, tend to have white blood cells with especially truncated telomeres.) The only such study showing clinical benefit was a year-long pilot study of TA-65 for early age-related macular degeneration, though it was funded by the company that sells it for $600 a bottle. They grossed more than $50 million before the Federal Trade Commission charged them with false and deceptive claims and practices.

That $600 buys you less than a gram of astragalus root extract. You can buy astragalus root extract in bulk 50,000 times cheaper for less than $20 a pound, should there ever be independently verified benefits. Astragalus root, well-known as huáng qí in China, is one of the most popular herbs in traditional Chinese medicine, included in hundreds of herbal formulas and evidently widely marketed for millennia as a “life prolonging” tonic. No data on that, but about 30 grams a day appeared to help with a type of autoimmune kidney disease called idiopathic membranous nephropathy in 50 randomized controlled trials, but not placebo-controlled trials; so, any placebo effects can’t be discounted.

Pregnant or nursing women are cautioned against using astragalus, and a theoretical concern was raised that it may activate a certain oncogene, a potentially cancer-causing gene. However, dozens of randomized trials of astragalus-based herbal preparations as an add-on therapy to chemotherapy for the most common type of lung cancer (non-small-cell) found, if anything, astragalus to be protective. Lung cancer is the leading cause of cancer death in the U.S. Adding astragalus to standard platinum-based chemo reduced the risk of death as much as 38 percent at the one-year-mark and 25 percent at two years. However, in almost all trials, the astragalus was just one of many herbs used in a formula, making the effects of astragalus impossible to tease out, and unfortunately, publication bias is widespread in the traditional Chinese medicine literature, where inconvenient results may be quietly shelved, though this in no way unique to that field.

Similar remarkable results, with similar critical caveats, were published for astragalus-containing formulas for colorectal cancer including improved quality of life. Same with cervical cancer, with remarkably reduced chemotherapy toxicity: less nausea and vomiting, less hair loss, less nerve damage, and less liver and kidney toxicity. Also, less lung damage from radiation treatments, and for stomach cancer, improved quality of life and quantity of life.