I grew up in the 1960s, inundated by commercials for margarines made from hydrogenated vegetable oils that “promised” those margarines would keep my cholesterol levels low and protect me from heart disease. Yet in 2015, nearly 50 years later, in the face of overwhelming scientific evidence of the harm they do, especially to the circulatory system and the heart, the Food and Drug Administration announced that artificial trans fats of the very sort that made up a good percentage of those margarines were no longer “generally recognized as safe,” and food manufacturers would have three years to remove these substances from their products altogether.