In 2000, Time magazine ran a memorable cover story about golden rice, a rice strain genetically modified to contain beta-carotene, a precursor to vitamin A. Vitamin A deficiency is a scourge in the developing world. The lack of it can lead to blindness in pregnant women, miscarriages and leads to as many as 500,000 children becoming blind each year. Golden rice could solve all that. In fact it’s one of the great arguments in favor of food from a genetically modified organism (GMO)–that altered rice like this will solve a lot of the developing world’s nutritional problems. So how...