IS GRASS A PROVEN TONIC?

Marijuana, as medicine, presents a paradox: It can ease the symptoms
of chronic disease. But it's usually smoked, and smoking is generally
thought to be bad for you.

After evaluating decades of research, the Institute of Medicine ran
into just that wall. "The report found potential medical benefits in
the active ingredients of marijuana," says Janet Joy, director of the
IOM's 1999 study, "but it's due almost completely to one particular
molecule that's packaged in an unhealthy way."

The molecule, called THC, is the most potent of the plant's 400-plus
chemical ingredients and has received the majority of scientific
scrutiny. In pill form, THC has been shown to reduce nausea, increase
appetite, and ease pain. But the pill, called Marinol, often takes
hours to kick in, and the high can be disturbing, intense, and long
lasting.

One toke. The argument for smoking is that it delivers relief
immediately, and dosage is easier to control. But the evidence is
largely anecdotal. In perhaps the only recent clinical trial, Donald
Abrams of the University of California-San Francisco found that male
AIDS patients who smoked marijuana three times a day for 21 days
maintained robust immune systems and gained more weight than did
patients on a placebo pill. Supporters of such research say isolated
THC is less effective than the whole plant, and that low doses do not
pose a serious risk of lung cancer. No one has ever died from a
marijuana overdose.

Even smoking's opponents--who say other drugs can treat the same
symptoms just as well--admit that marijuana can help patients when
nothing else works. Scientists are looking for better ways to
administer THC, including inhalers, skin patches, even suppositories.
For many patients, smoking may remain a more appealing option.