Purple yams are rich in antioxidants, including anthocyanins and vitamin C. Antioxidants help protect your cells from damage caused by harmful molecules called free radicals. Free radical damage is linked to many chronic conditions, such as cancer, heart disease, diabetes, and neurodegenerative disorders. Purple yams are a great source of vitamin C, which acts as a potent antioxidant in your body. In fact, studies have shown that consuming more vitamin C can increase your antioxidant levels by up to 35%, protecting against oxidative cell damage.