The worm has a lifespan of only two to three weeks, so it is possible to carry out experiments in a brief period of time. It is fairly easy to disable various genes, thus making it easier to determine their functions, and the worms can be frozen and stored, then awakened to do their job.
So a researcher who needs a worm with one gene silenced can go to the worm store and buy a bunch. It's really that easy.
It also turns out to be fairly easy to manipulate the lifespan of the worm. Researchers at Emory University, for example, found they could add 50 percent to the longevity of C. elegans with drugs designed to eliminate free radicals, toxic byproducts of metabolism. And scientists at the Howard Hughes Medical Institute found they could extend the lifespan by about 30 percent with a drug used to treat depression.
But C. elegans hit center stage a few years ago when scientists announced that resveratrol, a natural compound, also extended its lifespan. Resveratrol is found in red wine, so it was a very popular discovery.
The fact that the worm's lifespan can be stretched so much may not bode well for similar results in humans. We are living longer these days, but not all that much, despite centuries of medical progress. We may be similar to a worm, but we're a tad more complicated.
And many herbs, it turns out, don't do much for C. elegans either. Luo and her team, which includes researchers in Korea, tested several herb-based supplements, including green tea, breaking them down into their component parts so they could analyze all the herbs individually, and in concert with other herbs.
"Among all individual herbs tested, only two herbs, Panax ginseng root and Cinnamomum (cinnamon) cassia bark significantly extended the life span in C. elegans," they wrote in their study.
They also found that cinnamon is a star performer.
"A systematic evaluation of more than 30 herbs found that cinnamon is among the most potent antioxidant herbs," they reported.
The research also revealed that both of those herbs reduced the expression of amyloid, a "hallmark in the human brain of pathological development of Alzheimer's disease."
By turning to the tiny earthworm, Luo and her colleagues have established a way to examine even complex compounds to determine which components are essential. She explained that in some cases a certain "synergism" is required, so some herbs might detoxify while others help cells fight off cancer, for example. If herbs are removed without understanding their role, the drug might be weakened.
Perhaps the biggest concern among medical professionals, however, is not over whether the herbs do good. It's whether they do damage instead.
In the absence of clinical trials that determine the efficacy of drugs - even if they cannot be patented - many questions will persist. And it is still not known if herbs that work for an earthworm also work for humans.
But we are, after all, more similar than anyone thought just a few years ago.