In the 1950s to '70s, food additives and contaminants were considered important risk factors for cancer and other chronic diseases. Opinion leaders like F. Eichholtz and W. Kollath in Germany and R. Carson and J.J. Delaney in the United States maintained that the exclusion of man-made chemicals from the food supply would decisively contribute to better health. In contrast to these views, world-wide scientific opinion now emphasizes the role of personal lifestyle, e.g., over-nutrition, unbalanced diets, smoking, and excessive alcohol consumption in the causation of chronic diseases. Dietary guidelines now recommended for the prevention of cancer are largely identical with those recommended for the prevention of cardiovascular disease. Indications are that oxidative damage to DNA contributes importantly to both these diseases. In research the role of antioxidants and other protective substances in foods receives as much attention today as man-made carcinogens received in the past. Media reporting and nutrition counseling have taken very little notice of these fundamental changes in scientific opinion.