Now, Dr. D'Adamo--armed with new studies on genetic links between blood types, disease, and behavior--looks at the psychological and medical peculiarities that seem to predominate in one blood type or another. Type O's, for example, have lower than average amounts of a brain chemical called dopamine, leading to poor concentration, hyperactivity, and temper tantrums. A's tend to manufacture too much cortisol, a stress hormone that can lead to hypertension and has even been implicated in Alzheimer's disease and cancer. Type B's and AB's clear nitric oxide out of their systems faster, allowing them to calm down more rapidly than other blood types when stressed.

Dr. D'Adamo offers detailed lifestyle modifications for each type, including exercise programs, long lists of food to either seek out or avoid, and suggested treatment of specific illnesses. Some of this gets pretty arcane, including his recommendation of bladder wrack (a seaweed) for ulcer treatment of Type O's.

A big part of the appeal of this book series is that anyone reading it can become a participant by joining Dr. D'Adamo's blood-type registry at www.dadamo.com. Live Right for Your Type is peppered with testimonials from these registrants, giving the reader a sense that a true transformation in health, appearance, weight, and well-being is just a few diet and lifestyle changes away. --Lou Schuler