The sweet potato is not related to the spud family and has different nutrients too. While potato is a tuber or a thickened stem, the sweet potato is a storage root. Loaded with nutrients, sweet potatoes are among the American Diabetes Association’s top 10 diabetes super foods.
Though it originated in Latin America, Asia is its largest producer. It is the sixth most important food crop after rice, wheat, potatoes, maize and cassava.
Rich in starch and fibre, the nature of carbohydrates in sweet potato differ from that of potatoes. Its high fibre content contributes to a lower glycemic index (44), almost half of potato’s glycemic index (80). This makes the sweet potato a useful carbohydrate source for weight watchers and diabetics.
According to a 2004 study led by a University of Vienna professor, Dr Berhhard Ludvik, published in the journal Diabetes Care, type 2 diabetes patients who ate sweet potato saw a significant reduction in blood glucose levels and overall improvement in glucose control. When you eat sweet potato with its skin, it gives you more fibre than oatmeal.
Cooking methods also affect the glycemic index of sweet potato. For diabetics, certain cooking methods are more conducive to managing blood sugar levels. Boiled or mashed sweet potatoes are not recommended as they can be digested faster, thus increasing their glycemic index and causing blood sugar levels to spike. Similar to fibre, fat will slow the rate of digestion and therefore maintain the low glycemic index, so a good cooking method for diabetics is sautéing in oil or roasting without removing its skin.
According to the American Diabetes Association, sweet potato has high fibre content, antioxidant nutrients like Vitamin A, Vitamin C, zinc, and other micronutrients such as potassium, magnesium, iron and Vitamin B, which help in diabetes management and prevention of diabetes complications such as heart attacks.
Orange-coloured sweet potato is an important source of beta-carotene, the precursor to Vitamin A. Just 125g of fresh orange sweet potato contains enough beta-carotene to provide the daily pro-Vitamin A needs of a pre-school child. About 100 g baked sweet potato has about four times the recommended daily allowance (RDA) of Vitamin A and almost half that of Vitamin C. Nutrients in sweet potato are also useful for people with obesity, high cholesterol, high blood pressure and promotion of good health in general. A 2011 animal study conducted at School of Medicine and Life Sciences, Zhejiang University City College, China, reported that purple sweet potato flavonoids can decrease levels of blood glucose and lipids.
A staple food source for many ancient populations, sweet potato has been found to have special cancer-preventing properties, which are present in its purple variant. Anthocyanins, which give the purple colour to sweet potatoes, are powerful bio-available antioxidants, which are utilised efficiently by the body.
Sweet potatoes are a healthy source of carbohydrates too.