A. Judith C. Thalheimer, RDN, LDN, managing editor of Tufts Health & Nutrition Letter, answers: “Chlorella is a type of algae. It is harvested and processed into nutritional supplements. As long as the cell walls are broken down before ingestion, chlorella provides protein, fat, carbohydrate, fiber, vitamins, minerals, and chlorophyll, but the actual amount of these compounds in a given supplement is small and varies widely. When consumers purchase a chlorella supplement, it’s difficult to know exactly what they’re getting.
“These supplements are advertised to do just about everything—increase energy, control blood pressure and cholesterol, reduce joint pain, help with digestion and regularity, improve memory and mood, balance blood sugar, and even improve bad breath. In fact, there is insufficient evidence to say definitively that chlorella does any of these things.”