Beyond the Helix DNA AND THE QUEST FOR LONGEVITY by Carol Kahn (Times Books: $16.95; 265 pp.)
That it may be the only book on longevity that doesn’t endorse an anti-aging regiment constitutes one of the book’s greatest strengths. Instead of recommending a treatment program based on scanty and incomplete evidence, as so many authors have, science writer Carol Kahn has chosen to focus on the scientific research itself, and on the scientists who perform it.
In so doing, she shows us that the only proven way to extend life is to follow a few simple rules of good health, such as to quit smoking, to drink in moderation, and to maintain normal weight. There’s no good evidence that the vitamins, enzymes and diet supplements touted by some writers help at all, and they could well do more harm than good. Kahn quotes one scientist who says, “There is no information I know of that one could act on, not one thing. And by rushing into something, you might screw yourself up. I still think the best rule of thumb--and it’s sad to say--is, just doing everything in moderation.”
Still, according to Kahn, now is a time for optimism. A number of independent lines of evidence seem to be converging, and many scientists now believe that we’re close to an understanding of the cellular basis of aging. With understanding will come treatments that could allow more of us to maintain our vigor up to and beyond age 115, which is generally regarded as the maximum human life span.
The key to aging seems to lie in our DNA, the genetic material that controls each of our 60 trillion cells. This DNA is under constant assault--by carcinogens, by the toxic byproducts of the food we eat and the oxygen we breathe, and even by sunlight. According to one estimate, these agents damage our DNA 1,000 times per cell per day. The real question, says one scientist, is “not why we do die, but why do we live as long as we do?”
Indeed, were this damage to go unrepaired, we’d all be riddled with cancer in infancy. But our cells have evolved defense mechanisms that patch damaged DNA and inactivate many of the toxins. Many researchers are now convinced that these defense mechanisms are under the control of a single complex of genes. If we can learn how these genes work, we may be able to increase their activity with hormones or drugs or genetic engineering, thereby extending life. Kahn reports that some such drugs are already under development and may be available within a few years.
According to another group of researchers, we literally unravel as we grow older. Normally, most of our DNA is wound tightly into “supercoils.” Only uncoiled genes are active. As we age, the supercoils relax and our cells begin to produce inappropriate proteins. One experiment revealed, for example, that old brain cells start to make hemoglobin, a protein ordinarily found only in blood cells.
If this were a book dealing only with the latest results in gerontology, it would be a fine one, but it is enhanced considerably by Kahn’s interest not only in the products of scientific research, but its process as well. “The pursuit of a scientific goal,” she writes, “contains the elements of a good thriller--the false clues, the blind alleys, the hypotheses that are enthusiastically embraced and discarded, the crescendo-ing excitement as first one researcher, and then another, picks up the right trail.”
And in “Beyond the Helix” she makes us feel the thrills and the frustrations of the chase. Like the “The Double Helix,” James Watson’s famous account of his discovery of the structure of DNA, “Beyond the Helix” shows us science and scientists as they really are, warts and all. Kahn shows us the inevitable, bitter priority fights. She shows us the scramble for funds from such agencies as the National Institute of Aging, whose director openly lists life extension last on his list of priorities. And she shows us the ludicrous spectacle of two respected scientists studying the same single-celled organism at the same university, feuding and not speaking for years.
Despite these all too common distractions, science does march on. Kahn takes us into the labs and into the thoughts of about a dozen leading gerontology researchers, none of whom is well known to the public, and all of whom are positively possessed by their quest. She makes us realize that these scientists are driven as much by the desire to extend knowledge as by the desire to extend life.
“Beyond the Helix” is a lucid, thorough, and responsible account of a most exciting branch of biology. It will appeal to the reader interested in up-to-the-minute longevity research, to the reader interested in how science really works, and even to the reader who just enjoys sitting down with a good mystery.
