Mind Over Matter - Debunking Alternative Medicines - NYTimes.com Others might have chosen to flee the public arena after that, but not Dr. Offit, the chief of infectious diseases at Children's Hospital of Philadelphia, whose appetite for the good fight seems only to have grown. Over the last decade he has become a leading debunker of mass misconceptions surrounding infections and vaccines, and now he is taking on the entire field of alternative medicine, from acupuncture to vitamins. This territory is not all that far from his usual stomping grounds; some of vaccination's rabid opponents are enthusiastic supporters of unconventional medical interventions. Nor has Dr. Offit's own stance changed: He speaks for rational, scientific medicine (and medicines) whose efficacy has been confirmed in impartial, reproducible clinical trials. Everything else, no matter how venerable, highly recommended or self-evidently 100 percent terrific, he places on the spectrum between unproved and dangerous. His long "consume at your own risk" list contains most of the treatments and substances composing the nation's multibillion-dollar alternative-medicine industry. The book's subtitle may suggest that "sense" and "nonsense" will get equal play, but Dr. Offit spends most of his time discussing and dismissing nonsense. In fact, the sensible treatments he identifies can be summed up in one short paragraph. And here it is: Dr. Offit gives a nod to 4 of the 51,000 supplements on the market: omega-3 fatty acids to prevent heart disease; calcium and vitamin D to prevent osteoporosis in postmenopausal women; and folic acid during pregnancy to prevent spinal-cord defects in newborns. As it happens, several months ago - presumably after the book went to press - an influential national task force found the evidence for calcium and vitamin D to be unconvincing. So that reduces the list of sensible supplements to two. This doesn't necessarily mean that the remaining 50,998 products are worthless, Dr. Offit points out, or that acupuncture, chiropractic, massage and other unproven procedures don't bring real relief. In fact, most of them probably work reasonably well, enabled by the extraordinary magical powers of the human mind. Dr. Offit's chapter on the depth, range and power of the placebo response is comprehensive and convincing, perhaps one of the best brief reviews of that subject to be found. And with it, his discussion of sensible alternative medicine draws to a close. This dismissive bottom line may not be death-threat material, but it is certain to annoy readers seeking validation of their own favorite alternative support systems. Those without a personal stake, however, will be most entertained by Dr. Offit's fluent and enthusiastic trek through the fields of dreams various entrepreneurs have sown over the years. He considers vitamins in doses large and small, then heads out through bioidentical hormones to chelation therapy and an array of bogus cancer cures. He examines the claims of those claiming to cure autism and chronic Lyme disease. He marvels at the chaos elected officials can create when they decide to get involved: One of the biggest muddles in recent history was the passage of the 1994 Dietary Supplement Health and Education Act, which ensured that any substance labeled a supplement would receive minimal federal oversight and regulation. The terrain is full of repeating patterns. Among them, unfortunately, are the stories of children and adults who died of treatable diseases because they shunned conventional medicine for hocus-pocus. Then there are the public figures, often actors, who reinvent themselves as medical authorities: Dr. Offit focuses on the hormone-fueled Suzanne Somers and on Jenny McCarthy, a proponent of the vaccination-autism link and a champion of dozens of miracle substances. Equally charismatic and dangerous are the great scientists who launch themselves off the cliff of plausibility and never return. Linus Pauling was one, a chemist whose brilliant early work earned two Nobel Prizes; he went on to champion megadose vitamin treatment for all ills, and despite study after study showing they were worthless, he never publicly recanted. Dr. Andrew Ivy had a similar career. Dr. Ivy was revered in American medicine during the decades before World War II, and after the war he used material from the Nuremberg trials to lay down enduring modern standards for human experimentation. Then he fell hard for a bogus cancer cure, was indicted on multiple federal counts and died in disgrace. Humans wise and foolish clearly have a remarkable talent for deceiving themselves and others - sometimes with dollar signs glinting in their eyes, but sometimes with only the conviction that a smart, self-confident person armed with the right potion should be able to reconfigure nature. Dr. Offit makes passing reference to the memorable debate that took place in the Indiana State Legislature in January 1897 regarding the value of pi, the ratio of every circle's circumference and diameter. A lawmaker pointed out that 3.14159 was impossibly inconvenient, and that 3.2 would be far easier to work with. Ultimately Indiana House Bill 246, proposing a change in the value of pi, was defeated in the Senate. Still its story endures, like those of megadose vitamins, Krebiozen, antineoplastons, coffee enemas, intravenous hydrogen peroxide, emu oil and homeopathy - all examples of mankind's extraordinary capacity for wishful thinking.