Today's Tip: Yams vs Sweet Potatoes...which should you choose & is there a difference?

You hear a lot these days about SuperFoods, & one that has made every SuperFood list I have seen is the sweet potato. If you've gone to the store to buy some, you have probably seen both "yams" & "sweet potatoes" available for purchase. So what's the difference?

Well it may surprise you, but in the United States, most tubers sold as yams are actually members of the sweet potato family. In actuality, the “yams” you see with the rich orange flesh and reddish-brown exterior, are, botanically, sweet potatoes. In fact, it’s quite likely that the vast majority of us have never tasted a true yam. The reason for this discrepancy is simple marketing: back in the mid-20th century, when orange-fleshed sweet potatoes were introduced into the United States, they were labeled “yams” to avoid confusion with the common white-fleshed sweet potato Americans were already enjoying. Both varieties of sweet potato, including "yams" can be widely found in supermarket. However, true yams may not even be available at your local grocery store. They should, however, be available at your local Asian or African food market.

Yes, it's true...there are really two types of sweet potatoes (actually, there are more than two but for today we'll just talk about the two most readily available).  There are sweet potatoes with golden skin, creamy white flesh and a crumbly texture, and then there are the ones with copper skin & an orange flesh that is sweet and soft - often labeled as "yams". All sweet potato varieties generally have the same shape and size -- they are tapered at the ends and much smaller than true yams.

So which one should you choose?? Well, let's look at the differences.

An 8-ounce serving of yams provides 150 calories compared to 200 calories for sweet potatoes, and both are nutrient-dense foods. However, sweet potatoes hold an edge over yams in certain nutrients.

Both yams and sweet potatoes offer plentiful complex carbohydrates--40 grams for yams and 45 grams for sweet potatoes per 8-ounce serving. Fiber is abundant in both vegetables as well, with yams supplying 5 grams and sweet potatoes 7.5 grams.

The biggest nutritional difference between yams and sweet potatoes is their vitamin A content. An 8oz sweet potato supplies a whopping 270% of your daily requirement for this vitamin, which is needed to keep your skin and soft tissues healthy, while the same portion of yams offers only 1%. Both vegetables are good sources of vitamin C, vitamin B6, thiamine and pantothenic acid, although 1 cup of sweet potatoes provides 20-50% of your daily needs for each of these vitamins, roughly double the amount that yams contain. These vitamins help your body repair wounds and damaged tissues; they also help metabolize your food and keep your cells in good condition.

Other nutrients...a 1-cup serving of sweet potatoes gives you half your daily requirements for potassium, copper and manganese. The same amount of yams provides 20% of your daily needs for these vitamins.

So when you are at your local grocery store and you see a tater labeled "yam", you could ask the store manager if it is a true yam.  You might just teach him/her something!  But since sweet potatoes (orange or not) apparently have the nutritional edge, maybe just buy a few of each variety and enjoy!

Sources: Mark Sisson, American fitness author and blogger - marksdailyapple.com; Jan Annigan, writer, who holds degrees in sports medicine, human performance & animal science.