Sweet Potato vs. White Potato
Sweet potatoes are a staple at holiday dinners and regular or white potatoes are enjoyed year-round. To learn more about these vegetables, we got in touch with Dr. Alison Duncan, Professor, Department of Human Health and Nutritional Sciences, University of Guelph.
We’ve heard that sweet potatoes are nutritious – is that true?
Dr. Duncan: Sweet potatoes are packed with nutrition! They are high in dietary fibre, essential vitamins and minerals and especially beta-carotene, which we can convert into vitamin A in our body. You can easily get your entire vitamin A daily requirement from a sweet potato. Vitamin A is great for your eye health and your bones. Additionally, vitamin A helps fight against skin, lungs and mouth infections.
What’s the nutritional value of white potatoes and how do they compare to a sweet potato?
Dr. Duncan: White potatoes and sweet potatoes both pack a nutritional punch and are part of a healthy diet. They contain similar amounts of carbohydrates, fat and protein, vitamin C and potassium. Sweet potatoes have more fiber and beta-carotene (which our body converts to vitamin A). But really it is a nutritional tie and you can’t go wrong, any kind of potato is amazing and should be included in a healthy diet.
Dr. David Douches, director of the Potato Breeding and Genetic Program at Michigan State University, gave us some history of how white potatoes have developed.
Dr. Douches: “It was a Rev. Goodrich in upstate New York who got some potatoes and started making crosses. Our Russet Burbank potato, which is used for making french fries, comes from that lineage. Russet Burbank actually came from a chance seedling that was selected by Luther Burbank in the 1860s. That potato hung around for a while and a Russet mutation was found in it in the late 1800s and early 1900s. The Russet Burbank potato was well adapted to growing in the Pacific Northwest and so during World War II, they were using that to make potato flakes for the war effort. It was after World War II that the frozen fry industry started up as an innovative idea.”
What’s the healthiest way to cook sweet potatoes? And do you lose their nutritional benefits if you add something like… marshmallows?
Dr. Duncan: Any way you cook them is healthy. You will always get some nutritional value from the sweet potato itself, but of course if you prepare it with other things like marshmallows or a less healthy fat, you will be getting other things. But overall, you are still eating sweet potatoes and it is worth trying them without marshmallows as they are very sweet on their own!
What’s your favorite way to cook them?
Dr. Duncan: I like them best simply prepared in the microwave. I just take a sweet potato, wash it, pierce it with a fork multiple times, wrap it with a damp paper towel and microwave for two 5-minute periods. I then let it cool, cut it in half and then simply eat it all with nothing added as it is sweet enough on its own!
Anything else you want people to know about sweet potatoes?
Dr. Duncan: Sweet potatoes actually come in other colours besides orange. For example, there are purple sweet potatoes which are high in anthocyanins, a phytochemical that not only gives them their purple colour but offer antioxidant potential.
What can we expect from potatoes in the future?
Dr. Douches: “They’re going to be self-driving and they’re going to fly like drones! No, what’s happening is the consumer is going to continue to get potatoes that are more healthful and are packed with more nutrition. But what they won’t see is that these potatoes are also performing on the farmers’ fields, giving them more resistance to the biotics problems like diseases and insects and also to problems like water needs or climate stresses.”
Sweet potatoes are a nutritious vegetable high in fibre and beta-carotene. White potatoes contain similar amounts of carbohydrates, Vitamin C and potassium, but less fibre and beta-carotene. Any kind of potato can be included in a healthy diet.
Originally published Nov. 20, 2017.