Summary
Sweet potato (Ipomoea batatas (L.) Lam) has become a research focus in recent decades because of its nutritional and functional properties. Its leaves, stems and roots are a valuable source of bioactive carbohydrates, lipids, proteins, carotenoids, anthocyanins, phenolic acids and flavonoids. These bioactive metabolites possess many biological activities, such as antioxidant, antidiabetic, anticancer, hepatoprotective, antimicrobial, antiulcer and immunostimulant activities. Moreover, previous investigations proved that bioactivity varies qualitatively and quantitatively among sweet potato cultivars. So, the purpose of this review was to summarise the preclinical and clinical studies that have been conducted on different varieties of sweet potatoes, aiming to find the gap between them. This may consequently help in recommending additional clinical investigations on sweet potatoes maximising their potential as a functional food.