Root vegetables again

Today I made the root vegetables again but this time I cooked/steamed them on the stove with a bit of water and a lid.  No heated oil; the much cleaner and less carcinogenic option.  (Less carcinogenic except for the second batch which I forgot about and let burn into the bottom of the pot.  My apartment smells of burnt veggie flesh.)

The plot twists: the yams I thought I'd been eating, are actually sweet potatoes.  According to this fact sheet, sweet potatoes are even better for me, so I'm fine with it:

Unique Proteins with Potent Antioxidant Effects

Sweet potatoes contain unique root storage proteins that have been observed to have significant antioxidant capacities. In one study, these proteins had about one-third the antioxidant activity of glutathione-one of the body's most impressive internally produced antioxidants. Although future studies are needed in this area, count on these root proteins to help explain sweet potatoes' healing properties.

A Sweet Source of Good Nutrition

Our food ranking system also showed sweet potato to be a strong performer in terms of traditional nutrients. This root vegetable qualified as an excellent source of vitamin A (in the form of beta-carotene), a very good source of vitamin C and manganese, and a good source of copper, dietary fiber, vitamin B6, potassium and iron. 

The intensity of the sweet potato's yellow or orange flesh color is directly correlated to its beta-carotene content. The beta-carotene in orange-fleshed sweet potato, which our bodies can use to produce vitamin A and is therefore called "Provitamin A," has been reported to be more bioavailable than that from dark green leafy vegetables. Purple-fleshed sweet potatoes, on the other hand, are a good source of anthocyanins and have the highest antioxidant activity among sweet potato varieties. In one study, the antioxidant activity in purple sweet potato was 3.2 times higher than that of a blueberry variety! Interestingly, the antioxidant activity in sweet potato skin, regardless of its color, is almost three times higher than in the rest of the tissue.