In his latest book, neurologist Perlmutter (The Better Brain Book) declares war on a common foodstuff, attributing a bewilderingly wide assortment of maladies to the consumption of gluten, a substance found in bread and other stock foods. Contrasting modern humans against idealized humans of the distant past, Perlmutter concludes that the former, whose average life expectancy at birth is about twice that of their Paleolithic ancestors, have gone off the proper track. He addresses the churlish objection that gluten has been part of the human diet for many millennia by firmly asserting that recent changes to crops have transformed a once-safe food into a terrible scourge. The book features health advice, a number of gluten-free recipes, and details on some relevant case studies. Lauded by such nonconsensus pundits as Mehmet Oz and William Davis, Perlmutter offers readers a comfortably simplistic model for thinking about carbs.