Shortly after posting my piece on Sweet Potatoes and Yams, I was enjoying a non-paleolithic adult beverage with Toby - locally known as, "The Man". He said that he enjoyed the post, but that he would have liked to have seen tables, data, percentages and such. Basically, he wanted me to geek out, but also to bring in a "normal" potato into the mix for comparison. James, while eating his order of "sweet potato" fries also jumped into the mix, noting Vitamins and a whole host of other things for me to geek out on.
Hence, this post.
We each discussed what we thought were sweet potatoes and yams, then James started telling tales of tuber colors and grilling. Googling for such images is rather confusing, given the US's inability to name/advertise their tubers correctly. For clarification, when I buy a sweet potato and a yam from Henry's, this is what I buy:
The sweet potato is on the left, and the yam is on the right.
When cut, the insides look like this:
Note the orange color for the yam. For any of you who get sweet potatoes with your meal, or get the frozen ones - both of which are typically orange - I'd be skeptical!
Referencing nutritiondata.com, I present to you, internet blog readers, the following (all data is per 100 grams of the tuber):
Glycemic Load (lower is better)
* Potato: 8
* Sweet Potato: 8
* Yam: 12
Inflammation Factor (the higher the number, the more anti-inflammatory [desirable])
* Potato: -46
* Sweet Potato: 123 (Good!)
* Yam: -73
Nutrient Balance (Higher is better)
* Potato: 51
* Sweet Potato: 55
* Yam: 45
CHO breakdown (Total/fiber/starch/sugar, in grams)
* Potato: 18.4/2.2/15.4/0.8
* Sweet Potato: 20.1/3/12.7/4.2
* Yam: 27.9/4.1/~/0.5 (Although I think the ~, which I interpreted to be 0, is incorrect. However, that data point is irrelevant).
Vitamins (Vitamins and %'s worth noting)
* Potato: C @ 33%, B6 @ 15%
* Sweet Potato: A @ 284%, B6 @ 10%
* Yam: C @ 28%, B6 @ 15%
In my opinion, the sweet potato is the supreme tuber choice of the three, since it is tied for lowest glycemic load, won in a landslide of anti-inflammatory properties, gets a slight nod to the nutrient balance, and with a high vitamin content primarily in Vitamin A (a strong anti-oxidant, score!)