The Harvard Nutrition Source article discusses food additives, which are substances added to foods to enhance their flavor, texture, or shelf life. It examines the potential benefits and concerns associated with various types of food additives, such as preservatives, sweeteners, and coloring agents. The article highlights the ongoing debate around the safety and regulation of food additives, noting that while some are considered safe, others may have potential health risks. It emphasizes the importance of understanding the role and impact of food additives in the modern food system.