Last month, a group of geneticists from UC Irvine published an article about Rhodiola root, confirming that feeding it to fruit flies makes them live 20% longer, and reporting a negative finding about how that might work: benefits of Rhodiola appear to be entirely separate from the response to hunger, the “CR Effect”. Why was the article featured in the prestigious journal, PLoS One, which is targeted at a broad audience of non-specialists?
You might imagine that if living longer was as simple as eating an herb that has been known to traditional medicine since the time of the ancients, then this would have been validated by Science some time in the last hundred years, and health food store would be advertising it and every doctor recommending it. Curiously, it hasn’t worked that way. To study life extension in people takes too long, so a preliminary screening is done in mice. To test a single candidate treatment costs about $100,000 and takes over two years. Because herbal medicines can’t be patented, there is no company motivated to put up the money, and aging has never been a high priority for government grants, and the Federal budget for science has been dwindling.
(Stephen Spindler of UCLA has taken on the project of testing dozens of compounds to see if they extend the lives of mice, and has advocated that it’s just too slow and expensive, and we might gather information more quickly and cheaply by looking at how the compound effects the mouse’s gene expression. This is expected to work because we know that gene expression changes in some characteristic ways in older mammals, and this is thought to be causally connected to aging. Is anyone asking, “Why don’t we try to artificially engineer a youthful profile of gene expression?” Well, yes …but that’s a digression for another column.)
Only a handful of compounds are known that have been documented to extend life span in mice: Deprenyl, metformin, melatonin, and rapamycin are three that come to mind. They are all prescription drugs. Melatonin is widely-available and cheap, useful for regularizing sleep and adjusting to change in time zones. Metformin is a genuine anti-aging compound, in my opinion. Its benefits are clearest for people who are overweight or diabetic; though I am neither, I take it myself, in subclinical doses. Rapamycin is not ready for prime time. It is a powerful immune suppressant and its long-term effects in humans have not yet been charted. Deprenyl (= Selegeline,Eldepryl, Emsam, or Zelapar) has been around for decades and its side-effects are better charted. It is a stimulant, a cousin of methamphetamine, and it will change the texture of your experience, in ways that you may like or may not. A fourth compound is a Vietnamese herb called dinh lang, for which I’ve been able to locate just this one intriguing study from 1992.
Fruit flies are much easier to breed and quicker to produce results. The tradeoff is that they are more distant from humans. It’s a striking and quite general finding from the science of aging in the last 20 years that genetic mechanisms of aging tend to be similar, conserved over great stretches of evolutionary time, so that there is reason to hope that a genetic pathway that affects aging in flies will have a corresponding pathway in people. There are more compounds known to extend life span in flies, and studying them for potential human therapies is one more promising, underfunded research project. Stem Cell 100 is a product that claims to induce very long life span in flies in experiments also conducted at Irvine. I’ve asked, but have been unable to find any peer-reviewed confirmation of this claim.)
The herb Rhodiola has a venerable history
Rhodiola has a legendary history dating back thousands of years. In 77 A.D., the Greek physician Dioscorides documented the medical applications of the plant, which he then called rodia riza, in his classic medical text De Materia Medica. The Vikings depended on the herb to enhance their physical strength and endurance, while Chinese emperors sent expeditions to Siberia to bring back “the golden root” for medicinal preparations. The people of central Asia considered a tea brewed from Rhodiola rosea to be the most effective treatment for cold and flu. Mongolian physicians prescribed it for tuberculosis and cancer. (Herb Wisdom)
The new paper starts with a quick summary of what is known about Rhodiola from modern experiments with animals. Reading it, one might garner the impression that experiments have been haphazard.
The root extract of Rhodiola rosea, also known as the golden root, has been widely used in traditional and integrative medical practices in Europe and Asia, where it has been purported to mediate a variety of beneficial effects in humans, such as improved mood, improved physical and mental stamina, and enhanced protection against high altitude sickness . The extract has also been reported to protect against tumor progression in mice, improve endurance in rats, improve blood glucose profiles in diabetic mice, and protect snail eggs against oxidative stress, heat, and heavy metals –. Our group has previously reported that R. rosea can extend the lifespan of the fruit fly, Drosophila melanogaster, protect flies and human cultured cells against oxidative stress, and decrease the production of reactive oxygen species in isolated fly mitochondria –.
(Does the prose remind you of the Findings page from the back of Harpers magazine?)
Why we might raise an eyebrow
The authors of this paper raise the possibility that Rhodiola ought to be of interest for further investigation whether it might be a candidate for human life extension. There are two reasons for optimism.
First: Treatments that extend life span almost always increase stress resistance as well. Animals that are pre-treated with caloric restriction prove to be much hardier when exposed to toxins. Any compound that increases stress resistance becomes an interesting candidate for experimental investigation for life extension potential.
In one experiment, mice were exposed to a 100% lethal dose of gamma radiation.. But among those mice that were prepared with Rhodiola 30 minutes beforehand, 90% of them survived the same treatment. The mechanism for such a dramatic protection is not completely understood. The gamma radiation acts like the proverbial bull in the body’s china shop, randomly breaking apart the delicate and complex molecules on which life depends. It’s unlikely that Rhodiola can do anything to stop that process. However, the body has its own chemical machinery for repairing the damage, and it is likely that these are upregulated in response to the Rhodiola. This makes sense at least on the surface, but it leaves you wondering: if there is such a survival advantage to enhanced presence of these repair enzymes, why does the body wait until it sees Rhodiola in order to produce a little extra?
Second: Most of the known interventions that extend life span in animals have proven to be related to the biochemical pathways that the body uses to resist stress and stave off aging during periods of starvation. CR mimetics are chemical or other means to harvest this potential without suffering hunger. But the potential for using these is in danger of become saturated in humans because we already have several good ideas for mimetics. Already 8 years ago, Aubrey de Grey was warning us that caloric restriction works much better in short-lived animals than in long-lived animals, and that the potential for extending human life by eating less (and mimetics) might be limited.
Rhodiola is interesting for all these reasons, and the fact that it is reported to increase energy, enhance concentration, and counter depression has tempted me to try it. I’ll let you know.