To air is human

The Ottawa Citizen, 26th January 2003

Oxygen is the breath of life. It is also slowly killing us all, Nick Lane reveals in a provocative new book. Reviewed by Dan Falk

Oxygen is really two books in one. The first few chapters follow the style of recent "less is more" science books -- a trend toward narrowly focused popular-science writing that has given us books on clouds (Richard Hamblyn), light (Ben Bova), the colour mauve (Simon Garfield) and the element hydrogen (John Rigden), to name just a few. In the second half of the book, however, author Nick Lane breaks out of the mould with a provocative discussion of oxygen's role in evolutionary biology, age-related diseases, and the life and death of human beings.

The pace is brisk: Within the first dozen pages, we've learned how and why multi-cellular organisms first took hold on our planet, why animals come in two sexes, why birds and bats have short lifespans, and why cloned mammals seem to die young. Early in the book we meet such key historical figures as Joseph Priestley and Antoine Lavoisier; later we're introduced to some of the more obscure researchers who have devoted their careers to unravelling oxygen's complex role on our planet and in our bodies.

Lane, a London-based medical educator and writer, emphasizes the paradoxical relationship between oxygen and living organisms: Oxygen is essential for life, but it is also a toxin. Without it, we quickly die, but too much exposure kills us also -- either quickly, through oxygen poisoning, or slowly, and inevitably, through aging.

This two-faced character of oxygen has always been there. The first single-celled organisms to evolve on Earth, some 3.5 billion years ago, did so in an atmosphere containing hydrogen, methane and ammonia, but very little oxygen; for them, oxygen was a poison.

Yet a few billion years later, the situation changed dramatically: Photosynthesis took hold, primitive plants began to pump oxygen into the atmosphere, and the first organisms for whom oxygen was a blessing rather than a curse appeared on the scene. Those creatures coped with oxygen's toxic effects by evolving "antioxidants" -- chemicals that slow or stop the oxidation of fats and proteins. We can learn a great deal from that ancient adaptation, Lane says, as we struggle to understand the myriad diseases linked to aging -- a topic that fills much of the book's second half.

It is here that Lane shifts from chemistry and physics to applied medicine, tackling oxygen's role in nutrition, health and aging. He explains in detail oxygen's role in diseases such as Alzheimer's, diabetes, cancer and malaria. The questions he addresses are of immeasurable practical concern: Why do our bodies' functions break down as we age? Can the diseases associated with aging be prevented -- or can their onset at least be delayed? Does the oxidation of our cells -- in particular, our brain cells -- impose a "natural lifespan" that can't be extended?

A major problem, Lane explains, is that humans evolved as hunter-gatherers for whom "success" meant living long enough to reproduce -- 20 years would have been good; 30 would be plenty. Today, thanks to modern medicine, we live much longer -- but longevity has come at a cost. In our final decades of life, we're forced to battle a host of age-related diseases that our bodies never had to cope with in our evolutionary past.

Lane tells us where modern medical research is on the right track and where, in his view, it is heading off the rails. We have learned a great deal from the genetics revolution, he says, but deciphering the human genome is also paving the way for "individualization of treatment," as scientists learn to pinpoint the slight differences in DNA between one person and the next.

Lane asserts that "we may be losing our way in the detail." Our attempts to slow the aging process in a wide array of living creatures, from worms to rats to monkeys, has met with some success; therefore, he concludes, "we should be looking at commonalities, not particulars" and suggests that gene-inspired drug treatments may be "misdirected."

Lane's exhaustive research is reflected in his tight arguments and crisp prose. Though the subject matter is sometimes complex, the central ideas are never difficult to follow. Oxygen will be of interest to anyone with a broad interest in chemistry or biology -- and to anyone interested in staying healthy as they grow old.

Dan Falk's first book, Universe on a T-Shirt: The Quest for the Theory of Everything, was recently published by Viking Canada.