Someone in Wiley's cover design and marketing departments did this book no favors. The cover depicts a largely faceless woman in a 1950s to 1960s era nurse's uniform. (The Little Lord Fauntleroy collar and watch the size of a blood-pressure dial are the giveaways. What kind of casting department do they have at that place, anyway?) The "nurse" is pointing to a brown medicine bottle (Clue 2: today everybody uses plastic) half-filled with pills. She smiles, and it's not the Mona Lisa's. The word "Bad" is in the "Inkpad" font or equivalent, sized in 96 point type and ugly black. The subhead opener, Misconceptions and Misuses Revealed, looks cribbed from a checkout stand tabloid, and the rest of the subhead, from Distance Healing to Vitamin O, seem a rather small sampling on which to pitch into existence a whole book. The cover promises a diatribe at best, polemic at worst. In a bookstore, only a screwball health nut could be seduced by such an unpromising cover.

Sad, this, because the book is anything but a screed for overly convinced fanatics. It is in fact a wide-ranging explanation of most people's health concerns written in most people's terms. It is especially good at reinforcing time and again that proper diet, nutrition, and exercise throughout life are the surest and cheapest keys to good health. Along the way, Mr. Wanjek dispatches no end of windmills, from the myth of racial exceptionalism to where, exactly, the tongue tastes sweetness and saltiness. The tiny little appendix (the one inside us, not the somewhat more commodious one at the end of the book) really does have a use after all and shouldn't be willy-nilly snipped out whilst the belly is open for other reasons. Kidneys, liver, skin, hair, the resident populations of microbes -- all these get a fair hearing and an even better explanation. As a periodic refresher on why it is a great idea to take care of oneself, this book is about as good as they come.

But it is not, as the cover implies, a debunking screed. Mr. Wanjek is very good at thoughtful explanations of when to take health claims at their word and when to look deeper. Chapter 24, for example, entitled "Organic Food," starts off with an appetite-vaporizing set of facts about the secretive industry that calls itself "Organic". Milk sold under that rubric is in fact produced by cows penned up in the same ghastly poop-palace conditions as the more traditional variety. They are simply fed organic food (whatever that might be) instead of the truly dangerous stuff the industrial-food lads have dreamed up. If we take off the rose-colored glasses with the word "organic" silk-screened on the surface, we find many similarities in the minds of "Organic" corporate nutrition designers and the minds of the tetracycline-and-ground-brains designers. Corporate, after all, is corporate. Strange things happen to thinking and values whenever that word enters the picture. So organic cows are penned up like their less well-fed sisters in row-stalls, mouth in a trough and teats in a machine that sucks them dry three times a day. They just get a nicer label for their fate. Soya milk, anyone?

You'll probably not want to keep this in mind next time at the McChicken place, but "free range" chickens range freely over a pecked-to-death enclosure with thousands of others, their beaks sometimes removed so they won't go on a murderous frenzy at the spark of something scary. And did you know that five California farms grow half the country's "organic" crops, right amidst other crops? How, in heaven's name, do they keep the insecticides and fertilizers from wafting in?

There are many similar examples of gut-spasming truth-telling, but Mr. Wanjek sticks to facts and graciously stays out of rubbing our noses in it. He also lays low some foot-soldiers of popular mythology that health-products industry generals use to scare the wits out of everybody. Remember the bottled Perrier scare a decade ago? To quote Mr. Wanjek,

"Perrier mineral water comes from a variety of sources beyond France, such as Texas and New Jersey. Somewhere, somehow, in 1990, unacceptable levels of benzene, a known cancer-causing chemical, made their way into the stylish green bottles. The benzene level was far from deadly or even cancerous. You would have had to drink a couple hundred bottles a day to get to a level that would significantly increase your lifetime risk of getting cancer; and by that time, at $2 a bottle, you would have died of poverty."

He gets into trickier territory in Chapter 32, "Herbs as Alternative Medicine." Here the line between boon and bunk is as greasy as a butcher's doorknob. On the one hand, he gives full credence to proven herbal medicaments like European milk thistle, the only known counter to a certain poisonous mushroom (and many similar examples of like kind). On the other, he says things like,

"...the herbal field us undermined by untrained herbalists, aromatherapists, astrologers, and New Age healers who blindly recommend herbal remedies with no clue how dangerous they can be."

Some of his examples are hilarious: "What good is the stress-relieving herb kava-kava when it is bound to a chocolate bar?" And for those of you who are more than a little dubious about the efficacy of whatever ingredients have the ability to enhance males by large inches in small weeks, you might want to check the pages of the teen magazines where a product called "Bloussant" will "wake up your body's growth process" and "actually stimulate the inner-cell substance in the breast...Your confidence level will soar." Note that the ad doesn't directly state that the boobs will actually swell; they will merely be stimulated to do so. Hell, a boyfriend will gladly do that and is far cheaper. What really does swell is the profit margins of WellQuest International (Bloussant's makers) for their blend of don quai, black cohosh, fennel seed, and saw palmetto, which, in the industrial quantities WellQuest orders them, go for pennies the pound.

There is a certain progression in Mr. Wanjek's book, like looking at the pictures drawn by a schizophrenic during the descent into irrationality. By the time he gets us to Chapter 38, "I'm Not a Reporter, But I Play One on TV," we've reached a sort of health industry Last Exit to Brooklyn. He sums up the condition of health reportage on mainstream TV,

"When cable television became mainstream -- with its endless choice of the marvelous, mawkish, and mundane -- network television took a belly punch. The challenge was to make news even more entertaining to attract viewers who could just as easily switch to cable without ever leaving the comfort of the sofa."

Mr. Wanjek's is an excellent book. Knowledgeable, fair, even-handed, clearly written. And above all, non-polemical. He has a point to make and he makes it well: There is bunk in the health industry as everywhere, but there are also some musts you have to know along with the must-nots. Those musts he reinforces time after time, in the simplest possible language: balanced diet, moderate amounts of stretching and exercise as long as you live, skip the noxious weed, treat alcohol with respect, and above all, moderation, moderation, moderation. For heaven's sakes, this is what the Buddha said, and it's a testimony to human willfulness that the obvious can be so hugely missed by so many people in so many ways for so long.

So skip the lousy cover and read the great book. It's going into my library of must-reads once every year.