Food/Nutrition Columnist
Sweet Potato Or Yam?
Nov 19, 2017 - 7:05:00 AM

( - At this time of year sweet potatoes and yams pop up on every menu. There are family favorites for holiday meals and chefs include them on seasonal menus. Which do you love, sweet potatoes or yams?

Although many people refer to orange-fleshed, moist potatoes as yams, they are actually sweet potatoes. As a matter of fact all “yams” grown in the US are actually sweet potatoes. The term yam is used to describe the copper or deep red-skinned, bright orange flesh sweet potatoes. Potatoes labeled sweets or sweet potatoes have a creamy colored skin and pale yellow flesh. They are all part of the sweet potato family, but none are actually potatoes. They are from the morning glory family which has edible, long, tuberous roots tapered at the ends.

Real yams, which are usually imported into the US, are dry, starchy root vegetables that are not relatives of US sweet potatoes.

Sweet potatoes are nutrition superstars. A 4-ounce medium sweet potato has 130 calories and it is loaded with fiber and complex carbs that are a good fit for either a weight control or diabetic eating plan. Sweet potatoes are also rich in magnesium, potassium, vitamin C, and vitamin A.

It has been estimated that 25% of Americans fall short on their daily vitamin A intake. The best sources come from animal products – liver, cod liver oil, milk, butter and eggs – but fruits and vegetables that contain carotenoids are also a valuable source.

Carotenoids are a form of provitamin A which gives sweet potatoes their vibrant orange color. Your body converts carotenoids to vitamin A as needed. Of the approximate 600 carotenoids found in nature, the one that your body changes most efficiently to active vitamin A is beta-carotene. A medium sweet potato can provide twice the amount of beta-carotene needed to meet your daily recommendation for vitamin A. The additional carotenoids which are not converted to active vitamin A enhance your immune system and decrease your risk of heart disease, age-related macular degeneration, and cataract formation.

Cooking actually breaks down chemical bonds naturally found in sweet potatoes, releasing more carotenoids and making them easier to absorb. In a study published in the Journal of Food Science and Technology, researchers found that close to 95% of carotenoids in sweet potatoes were still active after baking, 90% after boiling, and 85% after frying. Few vitamins have that retention rate after being subjected to the heat of cooking.

Peak harvest season for sweet potatoes is August through October but they are available year round because the root can be held for extended periods in proper commercial storage. At home sweet potatoes should not be refrigerated. Cold temperatures cause them to lose flavor and spoil more quickly. Stored in a cool, dry place you can keep sweet potatoes for up to two months.

Don’t let anyone make you feel guilty if you add a little butter to your baked sweet potato. An Iowa State University researcher found that the addition of some fat or oil helped to unlock the nutritional benefit of a number of substances found in vegetables, notably among them was beta-carotene.

In addition to serving candied sweet potatoes during the holidays, here is a list of versatile ways to enjoy this nutrition powerhouse.

© NRH Nutrition Consultants, Inc.
Jo-Ann Heslin, MA, RD, CDN is a registered dietitian and the author of 30 books. Available as eBooks from iTunes and Kindle/Amazon:

Diabetes Counter

Calorie Counter

Protein Counter

Healthy Wholefoods Counter

Complete Food Counter

Fat and Cholesterol Counter

Available in print from Gallery Books:

Most Complete Food Counter, 3rd Ed.

Your Complete Food Counter App:

For more information on Jo-Ann and her books, go to:


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