Did you know that iceberg lettuce is actually 96 percent water or that lightning strikes the earth 100 times every second? Were you aware that Napoleon delayed his attack at the battle of Waterloo because of hemorrhoids, perhaps costing him the victory? More to the point, did you have any idea that American adults consume between 10 percent and 20 percent of their calories as alcohol, drink 16 pounds of coffee a year and, collectively, swallow about 40 billion doses of medication annually?

These facts and thousands more are contained in Jane Brody's encyclopedia of wellness called "Jane Brody's The New York Times Guide to Personal Health." Don't be put off by the name. The book is easy to read after the title page. It is a fertile compendium of information about the human body drawn largely from Brody's health columns in The Times and stitched nicely together. She covers everything from lice and acne to death and dying. Her chapters on nutrition and exercise are particularly sensible and informative.

Brody's achievement is significant because her task is more treacherous than it might appear at first glance. Not only has she assembled enormous quantities of data on the human condition and weighed them as scientifically as possible, but she also has managed not to fall captive to any of the many orthodoxies that inhabit the health field. She is not an apologist for mainstream medicine (pointing out time and again that the average person can probably do more for his own well-being than doctors will), nor does she carry a flag for any of the various health cults that flourish today as they always have. Adelle Davis is not treated warmly and Edgar Casey isn't even mentioned. Brody points out the hypocrisy of the health-food enthusiasts who deplore "unsafe" chemical additives used by the food industry while endorsing the consumption of cyanide-laden apricot pits--Laetrile. Sugar isn't banished as "a white devil" and "wholism" isn't touted as the answer. In fact, she is not reluctant to speak out about charlatanism in health, devoting a number of pages at several points to quacks and how to recognize them.

Moreover, Brody eschews a common foible of health-writing. She does not assault the reader with citations and quotations from "authoritative" sources that -- accurate or inaccurate -- tend to be intimidating and generally useless. Now and again she refers to studies by groups such as the National Academy of Sciences or the National Cancer Institute, but most of her points are argued directly, without name-dropping. At the end of most sections in the book she provides a brief bibliography -- books from which her positions are drawn, books that will be of help to the interested reader.

Brody's credo is a simple one, firmly rooted in the middle-class self-help and wellness movements of recent years. "It is every patient's right and obligation to participate in his or her own care," she writes. "The 'activated' patient is less likely to be treated in a patronizing manner or suffer an adverse drug reaction or be operated on unnecessarily . . . The future of health care will be marked by a diminishing role of medical care providers (physicians and the institutions where they work) and an increasing role of the health care consumer -- you."

This is an appealing philosophy and well argued, but it has some flaws. By downplaying doctoring and maximizing personal responsibility, the individual becomes the primary custodian of health. This is fine so long as health reigns. But even runners get coronaries, and any number of ailments sneak up on the best tended of bodies. The self-help purist can be left with self-blame -- "if only I'd examined my breasts more often . . ." The system of medical care has the potential to provide succor and support for the individual in health and in sickness. Brody's arguments tend to minimize this possibility.

Then, too, Brody's book makes little of the connection between health and the larger political reality. At times, personal health care can be promoted or corrupted by circumstances that are distinctly not in the realm of the individual: environmental quality, availability of health care and communicable disease surveillance, to mention a few. The activated patient is in a good position to do a great deal for himself but not to take on these challenges. Brody's singular devotion to the body without mention of the broader social issues in health smacks of narcissism. While this will suffice for the hot-tub and bean-sprout set, many readers would have benefited from a chapter on social issues and personal health.

Still, the big picture aside, I will turn enthusiastically to "Jane Brody's Guide" to find out about car seats, Type A personalities, poison sumac and the amount of fiber in parsnips.