Most people think that yams and sweet potatoes are one in the same, when in fact they aren’t even part of the same family. Yams are a tropical root vegetable in the lily family, native and (still today) most common in parts of the world such as the Carribean, South and Central America, and parts of Africa and Asia. The sweet potato is in the morning glory family and originates in Central America and other tropical regions as well. It’s actually not an easy task to even find yams in the United States, and what many people refer to as yams (and think are yams) are actually orange or white-fleshed sweet potatoes.
Now, let’s take a look at the nutritional differences between the two (hint: sweet potatoes win)…
SWEET POTATO
Sweet potatoes are not only a superfood, but they are definitely one of (if not the) healthiest carbohydrates available. It is a tuber, and specifically comes from the Ipomoea batatas plant. Sweet potatoes have quite a different nutritional make-up than regular potatoes, and are far more nutritious.
Sweet potatoes are impressively nutrient dense, and include health benefits such as blood sugar regulation, cancer prevention, and vision support due to their high content of vitamin A.
Sweet Potatoes are High in Important Nutrients and Plant Compounds
Compared side by side with a white potato, sweet potatoes are quite high in key nutrients such as vitamin C, vitamin A, manganese, potassium, B vitamins and vitamin E. In terms of plant compounds essential for human health, sweet potatoes offer a great deal of beta carotene, coumarins and anthocyanins. The brighter the color of your sweet potato (think: bright orange flesh), the higher they are in antioxidants (1).
Sweet Potatoes are High in Fiber and a Healthy Starchy Carb
The sweet potato is primarily a carbohydrate, and contains only trace amounts of protein (about 2 grams per medium sized sweet potato compared to 27 grams of carbohydrates). While sweet potatoes do have a fairly high glycemic index, they are also incredibly rich in fiber, which slows down the processing of starch and sugar, causing less drastic of a blood sugar spike when compared to white potatoes or refined sugars/carbs (2). Fiber is essential for reducing your risk of type 2 diabetes and supporting healthy digestion.
Sweet Potatoes are High in Vitamin A
Vitamin A deficiency can be responsible for major vision problems and blindness, and poor immune health. Deficiency is quite common on a world-wide scale, and sweet potatoes are one of the single best food sources of this essential vitamin. The brighter the orange/yellow color of your sweet potato signifies an even higher vitamin A content, and children, pregnant and breast feeding women should be especially conscious of getting plenty of vitamin A in their diet.
Sweet Potatoes Maintain Stable Blood Sugar
Despite the fact that they are a carb-heavy food, sweet potatoes actually work well in maintaining stable blood sugar levels. Diabetics or others with metabolic disorders should still be conscious to eat sweet potatoes in moderation and alongside fat and protein (for example, spread it with a tablespoon of grass fed butter or coconut oil, and have alongside a chicken, fish or beef dish), but some studies have shown that cajapo sweet potatoes (one particular variety) can decrease LDL cholesterol levels and fasting blood glucose (3).
Sweet Potatoes Can Help In Cancer Prevention
This health benefit is mainly due to the high antioxidant levels in sweet potatoes, which can reduce and prevent damage done by free radicals, which are linked to cancer and other degenerative diseases. The purple skinned variety have shown to be particularly powerful in their antioxidant capabilities.
YAMS
Instead of a list format of yams nutritional value, we’ll discuss the differences between the yam and the sweet potato. Hands down, sweet potatoes win over yams in the nutritional department. Yams are starchier than sweet potatoes, and higher in calories. They contain far less beta carotene and slightly less vitamin C, and have a significantly higher glycemic index (they will spike your blood sugar more so than a sweet potato). Yams are higher in fiber and potassium than sweet potatoes.
Check out this side by side nutritional comparison of the yam and the sweet potato:
Sweet potato, 1/2 cup (100 grams), baked with skin (4):
90 calories, 0 grams fat, 20 grams carbohydrate, 3.3 grams fibre, 2 grams protein, 475 milligrams potassium, 20 milligrams vitamin C, 0.28 milligrams vitamin B6, 11.5 milligrams beta-carotene.
Yam, 1/2 cup (100 grams), baked with skin (5):
116 calories, 0 grams fat, 27 grams carbohydrate, 4 grams fibre, 1.5 grams protein, 670 mg potassium, 12 milligrams vitamin C, 0.23 milligrams vitamin B6, .07 milligrams beta-carotene.
So, Should I Always Choose A Sweet Potato Over A Yam?
In short: yes. If you eat a yam every now and then, you’ll still reap some nutritional benefits, and it’s still a far better choice than refined carbohydrates (bread, pasta, baked goods, etc). The good news is that choosing sweet potatoes over yams is pretty easy in the US, as sweet potatoes are much easier to come by in your local grocery store or farmers market. Sweet potatoes are also more likely to be locally grown, and yams are almost always imported.
Sweet potatoes make an excellent addition to a healthy diet, as they are a starchy carb that won’t spike your blood sugar but will keep you feeling full and help to reduce sugar cravings throughout the day. Eat up!