For instance, there's a section on why the FDA is not allowed to regulate supplements, and how messed up the supplement industry is:
Of the 450 supplement manufacturers inspected, at least half had significant problems. One, ATF Fitness, substituted ingredients without changing the product label. Others didn’t even have recipes for their products. And some manufactured products in buildings contaminated with rodent feces and urine—in one facility a rodent was found cut in half next to a scoop. (Location 1143)Offit covers all the usual suspects: cancer cures (including the alternative medicine practice that killed Steve Jobs), homeopathic medicine, the anti-vaccine movement, the vitamin pushers, acupuncturists, chiropractors, and even some doctors who're selling questionable "cures."
Offit doesn't just discuss the many failings of the supplement/natural foods/health foods, including the huge amount of effort and money spent so that the FDA does not even have the ability to stop herbal supplement sellers from making untrue medical claims. The depiction of this lobbying would be enough to make your blood boil. The stories of how parents would treat their children by taking them to quacks instead of using proven medicine is terrifying.
Offit does cover why certain alternative medicines appear to work by invoking the placebo effect. At one point, he reveals an interesting anecdote where Albert Schweitzer points out how witch doctors actually perform a service by providing placebos for psychological ailments, while pointing patients to effective western doctors for diseases which can be cured by medicine.
All in all, I found this book to be a great read, and very enlightening. Recommended. The book is currently available from Amazon at $1.99.