Nutrition of Sweet Potato

Besides simple starches, sweet potatoes are rich in complex carbohydrates, dietary fibre, beta carotene (a vitamin A equivalent nutrient), vitamin C, and vitamin B6.

Pink and yellow varieties are high in carotene, the precursor of vitamin A.

In 1992, the Center for Science in the Public Interest compared the nutritional value of sweet potatoes to other vegetables. Considering fibre content, complex carbohydrates, protein, vitamins A and C, iron, and calcium, the sweet potato ranked highest in nutritional value. According to these criteria, sweet potatoes earned 184 points, 100 points over the next on the list, the common potato.

Sweet potato varieties with dark orange flesh have more beta carotene than those with light coloured flesh, and their increased cultivation is being encouraged in Africa, where vitamin A deficiency is a serious health problem.

Despite the name "sweet", it may be a beneficial food for diabetics, as preliminary studies on animals have revealed that it helps to stabilize blood sugar levels and to lower insulin resistance.

Some Americans, including television personality Oprah Winfrey, are advocating increased consumption of sweet potatoes both for their health benefits and because of their importance in traditional Southern cuisine.

The peptic substance (0.78 percent total, 0.43 percent soluble) present in fresh tubers contains uronic acid (60 percent) and methoxyl (4 to 5 percent).

Other constituents include phytin (1.05 percent), two monoaminophosphatides (probably lecithin and cephalin), organic acids (oxalic acid), phytosterolin, phytosterol, resins, tannins, and colouring matter.