On Nov. 8, the Food and Drug Administration announced that dietary trans fats would no longer be “generally regarded as safe,” a decisive step that will lead to banning trans fats from foods altogether. Excluding trans fats from the food supply will result in an estimated 20,000 fewer heart attacks and 7,000 fewer deaths each year.

Trans fats have been part of the American diet for over 100 years and regarded as unsafe for two decades. The announcement led one thoughtful observer to see the development as reflecting how long the process of eliminating unhealthy foods from our diets can take. But there is another lesson for our times in the trans fats story.

Earlier this month, Monsanto and the other big chemical-seed companies, along with elements of the food industry, succeeded in defeating the Washington state referendum that would have required the labeling of GMO foods. A primary argument of the anti-labeling forces, repeated in this recent campaign, is that there is no evidence that GMO foods are unsafe, and thus mandatory labeling would be unnecessary and confusing. The trans fats story provides useful context for evaluating this claim.