Saving Weeds to Save Lives


Washington. At first, it seemed the only thing to do was applaud. Scientists had discovered that the bark of a common forest tree can help fight cancer.

But in science as in literature, very few stories worth telling don't have a villain in the plot, a "however" that must be overcome to reach a rosy ending. Sometimes people invent villains.

In this case, the "however" is the fact that Pacific yew trees with the magical bark are not common any more; timber companies clear-cutting forests in the Northwest have slashed and burned most of them. Yet it's not the timber companies who are cast as villains.

Surprise: It's the environmentalists. The same bad guys who want to save the last old-growth forests, who champion the rare spotted owl, now stand between cancer victims and the remaining Pacific yews.

Timbermen who blame environmentalists for unemployment, electric rock and teen-age acne were quick to see the public-relations potential in casting tree-huggers as a cause of unchecked cancer, too. Since the situation has been publicized, some cancer patients who saw hope in the drug derived from the Pacific yew are understandably angry.

The story is not quite that simple. To start with, laboratory experiments showed the drug taxol could kill some tumors more than 20 years ago. Six years ago, researchers at Johns Hopkins saw dramatic results against human ovarian cancer.

At that time, there were many millions more Pacific yews than there are today. The timber companies, in collusion with the U.S. Forest Service, rushed their clear-cutting operations to stay abreast of demand from Japan and ahead of environmental efforts to protect old-growth forests. In the process, about 90 percent of the yews, considered worthless trash, were destroyed.

If those timber operators had used selective cutting, taking only individual commercially desirable trees, the surrounding forest including the yews would have survived. If they had done all their cutting on private land, the national forests would remain a reservoir of timber and other commodities whose uses are still being discovered. Instead, they clear-cut millions of acres and destroyed the non-commercial growth.

When they replanted, they set out one species only, creating forest monocultures much more susceptible to disease, without

the natural variety that has produced taxol chemotherapy and uncounted other biological benefits to man.

When environmentalists tried to rescue the little remaining old-growth national forest, they used the northern spotted owl as their legal vehicle because it is protected by the Endangered Species Act. But the owl is merely an indicator species, one of many that will suffer if the last old growth is cut.

Now, it turns out the environmentalists were protecting the Pacific yew as well. Taxol from the slow-growing tree may be the most exciting development in chemotherapy in a decade. But the only way to use it for treatment and testing is to cut tens of thousands of yews -- and by more than mere coincidence, many of those yews survive in the same forests inhabited by the spotted owl.

One researcher at the National Cancer Institute says it's a conflict between owls and people, and he has no trouble choosing people. Those suffering from cancer strongly agree.

But those who want to protect the yew say many are growing on private land. They say taxol can be made from the yew's needles, instead of killing the tree for its bark. They say laboratories have not pushed hard enough to produce the drug artificially.

They also urge speedier research on whether other, more widespread species of yew are useful against cancer. Ornamental yews are grown all over the country. French scientists have found a European variety that offers a similar drug.

None of those approaches satisfies the patient who suffers from ovarian cancer today, whose illness might be eased by cutting the existing Pacific yews now, without worrying about whether the species survives. After all, some 50,000 species of plant and animal life are being wiped out every year, mostly by clear-cutting of tropical forests. What's one more?

One more that comes to mind is the common pokeweed, native to roadsides and trash lots across the American South. Not long ago, a drug made from its leaves was discovered to be 1,000 times more potent than the most favored existing treatment for the AIDS virus.

Many thousands of pokeweed have I cut. It's good I didn't get them all.

Copyright © 2020, The Baltimore Sun, a Baltimore Sun Media Group publication | Place an Ad