Lignans are a type of plant compound found in various seeds, grains, and vegetables. They belong to a larger group of substances known as phytoestrogens, which can mimic the hormone estrogen in the body. Common sources of lignans include flaxseeds, sesame seeds, whole grains, and berries. These compounds are believed to have potential health benefits, including antioxidant properties and support for heart health. Some studies suggest that lignans may help reduce the risk of certain cancers, particularly breast cancer and prostate cancer, although more research is needed to fully understand their effects.