WASHINGTON--In ``Sleeper,'' Woody Allen wakes up a couple of hundred years in the future to discover, among other things, that scientists have found that tobacco is actually good for you.
Well, not quite yet. But how about eggs? After years of egg phobia, we have learned that eggs may not be bad for you after all. And that butter is healthier than stick margarine. Every month, it seems, some accepted nutritional fact is overturned.
We have come to expect that diet fashions, though promulgated with scientific authority, change like the seasons. What we do not expect is a change in hormone fashions. Hence the shock this week when a massive study of hormone replacement therapy in postmenopausal women had to be halted three years early because the estrogen-progestin combination appeared to cause an alarming increase in invasive breast cancer, blood clots, strokes and heart attacks.
With that, the decades-old medical axiom about the protective powers of hormonal therapy was overturned in a flash. The reverberations were immediate. The company whose pill was being tested, Wyeth Pharmaceutical, lost 24 percent of its value in one day. Millions of women are now frantically calling their doctors for advice on whether to continue.
Most shocking, perhaps, is the simple reminder of how contingent are the received truths of modern medicine. We know how pre-modern medicine got it wrong, from centuries of leeching and bleeding to the lobotomies and shock therapies that destroyed the lives of so many psychiatric patients in the mid-20th century. But we think of modern science as infinitely more enlightened and more solid.
Not so. Less than a century ago, the most exalted scientific theory, Newtonian mechanics, was overthrown. Today its successors, general relativity and quantum mechanics, have yet to be fully reconciled. Thirty years ago, the scientific consensus was that we were headed for global cooling. Today it is global warming. The only thing I feel reasonably sure about is that 30 years from now meteorological science will have delivered yet a new theory, a new threat, a new thrall.
The problem is that even the most sophisticated scientific studies are limited by method, by modeling, by sampling and by an inevitable margin of error. Hence error and revision.
In medicine, because its solemn pronouncements are so widely propagated and so ingrained in people's lives, these revisions are particularly shocking. Yet common. When I was a kid, everyone got a tonsillectomy. It was a rite of passage. We now know that this was unnecessary surgery, indeed, worse than useless. We also routinely were given antibiotics for earaches. It now turns out that this did not hasten recovery, and in fact may have made us, and the population in general, more resistant to antibiotics.
For decades, breast cancer was treated with radical mastectomy, a disfiguring and deeply invasive surgery. The idea that many patients should instead be treated with lumpectomy was ridiculed for decades. It is now accepted medical practice.
My favorite myth is 98.6. If there was anything solid in my medical education, it was that mean body temperature was 98.6 F. Well, in 1992 the Journal of the American Medical Association published a study that actually measured it. It turns out to be 98.2 degrees. Where did the 98.6 come from? From the German doctor, Carl Wunderlich. In 1868. No one had bothered to check it since then.
The myths go on and on. That infectious diseases had been conquered. (Then came HIV.) That asthma is a psychological condition. That ulcers are caused by stress or stomach acid. For decades at midcentury, at the height of the psychoanalytic fad, the cream of the New York intelligentsia was sending its healthy children to five-day-a-week psychoanalysis.
So much nonsense. So much damage. Yet science has a hard time with humility. The rage today is regenerative medicine. Stem cells. Cloning. The growing, essentially, of replacement parts. It sounds wonderful, and it may yet turn out to
It is well to remember, however, that this is not the first panacea to be peddled. Yesterday, it was fetal tissue transplants for degenerative diseases and angiogenesis inhibitors for the cure of cancer. All of which looked wonderful on paper, but have not panned out.
This is not to say that this embryonic research will not pan out. It is only to say that when you hear Sen. Dianne Feinstein tell you that the research cloning her bill would promote will do wonders for your suffering Aunt Sarah, hold onto your wallet. She's talking about the speculative benefits from the most speculative of new technologies--at a time when, until yesterday, science could not tell us the effects of (BEG ITAL)existing