thenutritionwatchdog.com What's in your food? Discover which "healthy" foods are harming your health and which foods protect your body 
By: Cat Ebeling, RN, MSN-PHN, co-author of the best-sellers: The Fat Burning Kitchen, The Top 101 Foods that Fight Aging & The Diabetes Fix
Some people call them “yams” and others call them “sweet potatoes”. Is there a difference? And how do they compare with regular white potatoes?
Well for starters, sweet potatoes are the orange or reddish colored root vegetable you see at the grocery store. They are a member of the morning glory family, and not related to either yams or white potatoes. Sweet potatoes generally come from either Central or South America.
Sweet potatoes are usually longer and tapered at the ends with smooth colored skin, and can range in color from tan, to yellow, to orange, red, or purple. Sweet potato’s flesh inside also varies from white to orange or reddish orange, to purple-colored. Sweet potatoes are also usually softer and sweeter when cooked than either yams or regular white potatoes.
Yams are also a tuber vegetable. However, they come from a completely different family and are actually part of the lily family. Yams originated in Africa and Asia and there are about 600 different varieties of yams.
Yams have some distinct characteristics, and if you ever saw them, you would probably not confuse them with sweet potatoes. Compared to sweet potatoes, yams can grow very large. Size can vary from that of a small potato to up to 5 feet (1.5 meters). Yes, THAT big!!
Yams are more cylindrical, and have rough brown, almost tree-bark like skin that is very difficult to peel. The inside flesh is white, yellow, purple or pinkish. Yams are not sweet and smooth like sweet potatoes, they are more dry and starchy tasting.
Yams are not a common item to find in your grocery store, in fact, they are often difficult to find, except perhaps in an international market or ethnic food store.
White potatoes are something we are all pretty familiar with. White potatoes come from the Solanaceae family, which is related to tomatoes, peppers, and eggplant and considered part of the “nightshade” group of vegetables.
While there are literally thousands of different types of potatoes in the world, in general the types of potatoes we see here in the U.S. and in Europe are classified as russet potatoes, red potatoes, white potatoes, yellow potatoes (or Yukon Gold) and purple potatoes.
Sweet potatoes, yams, and regular white potatoes are actually all from different plant families and not related.
Sweet potatoes have become much more common and popular in the past ten or so years, and are often served baked, mashed, roasted. They are also a great alternative to French fries, and an alternative to regular mashed potatoes. Sweet potatoes are often pureed and used in recipes like soups and desserts.
And of course, sweet potatoes are a staple on the Thanksgiving table, sometimes served as sweet potato casserole with marshmallows (please don’t!) or made into a sweet potato pie.
If you are looking for a way to use those sweet potatoes in your kitchen, this is a must try recipe. You reap the benefits of all the nutrients from the sweet potato and turmeric as well. Curry Sweet Potato Soup (packed with antioxidants and fights inflammation)
African yams are usually boiled and mashed into a starchy paste called “Fufu”. Yams are not usually eaten baked; however, if they are baked they must be peeled before cooking. If you tried to cook them whole, they tend to explode, leaving a big mess!
How did yams and sweet potatoes get confused here in America? When African slaves came to the United States, they called our sweet potato “nyami”, or “yam” in English, because it resembled the yam from Africa.
The darker-skinned orange sweet potato variety was only recently introduced in the U.S., and in order to differentiate them from the original sweet potatoes, they were called “yams”. In my grocery store, I see the dark, reddish skinned sweet potatoes are called “garnet yams”, but they are not really real yams either. They are sweet potatoes.
In the United States, yams and sweet potatoes are often used interchangeably. Most all yams in a grocery store are actually sweet potatoes.
Sweet potato nutrition
Sweet potatoes contain a lot of nutrients (which is why they are so popular) including a massive amount of beta-carotene, the nutrient that our bodies turn into vitamin A. Eat sweet potatoes with butter to help this transformation work best. Sweet potatoes also contain about 35-40% of your necessary vitamin C for the day, manganese, vitamin B6, potassium, copper, niacin, thiamine and magnesium.
Sweet potatoes also help to stabilize blood sugar, and help the body become more sensitive to insulin. In fact, one study from Austria showed that a diabetic group who ate sweet potatoes actually had lower blood sugar levels at the end of the study than the control group. This is due partly because of the high fiber content, which slows the absorption of sugar into the body, and probably due to the high amounts of antioxidants, as well.
Antioxidants also help to reduce other chronic diseases including diabetes, heart disease, and cancer. The orange-y color in sweet potatoes means it is especially high in the antioxidant beta-carotene. A good rule of thumb for eating sweet potatoes is to pick the most colorful ones—these have the most antioxidants in them.
Sweet potatoes are also known to boost brain function, improve memory, and prevent oxidative damage in the brain.
Since sweet potatoes have about 400% of the pre-cursor to vitamin A, they are especially good for boosting the immune system, protecting the vision, and helping the skin.
What about yams?
Yams are higher in calories, carbohydrates and fiber and while they contain also contain a good amount of vitamin C, vitamin B6, potassium and manganese but are not as nutrient-dense or full of antioxidants as sweet potatoes are. (Hint—antioxidants have a lot to do with color).
Yams contain more potassium and manganese—both vital minerals that are good for bone and nerve health, heart function and metabolism. Yams do contain some similar nutrients like B vitamins but the health benefits of yams have not been studied near as much as sweet potatoes.
One more thing about yams—a derivative of an ingredient in yams is thought to help women’s hormone levels, especially progesterone. There is some evidence that yam extract may be a helpful remedy for some of the unpleasant symptoms of PMS and menopause.
White potato nutrition
White potatoes do have lots of healthy minerals, fiber and carbohydrates in them, but definitely are not the superstars that sweet potatoes are. White potatoes belong to a totally different plant family, are definitely different looking than either yams or sweet potatoes and have a whole different set of nutrients.
White potatoes contain plenty of vitamin C, folate (a necessary B vitamin), vitamin B6, potassium, manganese, but not the high levels of vitamin A or antioxidants that sweet potatoes have.
Blood sugar and the glycemic index
Sweet potatoes have a medium-to-high GI, around 60, and yams have a lower GI at about 50. White potatoes score the highest at 75.
So, when looking at all three types of potatoes, gram for gram, white potatoes will cause a sharper spike in blood sugar when eaten. So if you are diabetic or trying to keep your blood sugar low, you are better off eating sweet potatoes. Sweet potatoes are also higher in fiber than regular potatoes.
Which is best?
So—the winner of all three types of potatoes in terms of nutrition is sweet potatoes by a slim margin!
However, yams, sweet potatoes and white potatoes can all be healthy additions to the diet, as long as you are not restricting carbs. Preparation is the important factor; French fried ANYTHING is not going to be healthy, so eat baked instead of fried, and add a little dab of grass fed butter on it!
If you are watching your carbs, you are going to want to read this story below about what US heart surgeons are saying about this “health food”.
US Heart Surgeon Says Carbs are NOT the Problem (This “Health Food” is)…
According to this world-renowned Heart Surgeon below, a good portion of your weight gain, brain fog, and digestive issues may stem from a SINGLE vegetable you eat…
Listen, I realize this sounds far-fetched, but the science is groundbreaking. In fact, we now know of at least one so-called “health food” that could be wreaking havoc on your insides (and your results). What’s worse, it’s probably in your kitchen right now!
And today, my trusted colleague, Dr. Steven Gundry, is pulling back the curtain on exactly what it is:
==> This Vegetable Could be the #1 Danger in Your Diet
Your articles are very informative! I’m a diabetic so I’m careful with what I eat! Good article.
Great article, one correction FUFU is made from green plantains in Africa and Caribbean Islands, instead of from yams. Yams are eaten boiled without the skin or frien without the skin.
In some countries yams are eaten in conjunction with “Tasajo”, which is shredded fried horse meat. Which unbelievably is legally imported to the US, mostly from Argentina and Uruguay.
This incorrect.
Yam is made into fufu
Likewise green plaintain, Cassava
Even rice.
Nigerians have pounded yam so she is correct
Thank you for the beautiful write-up. I have not been able to eat the American sweet potato because they don’t taste or look like what we have back home. Pounded yam is called “iyan” in the southwest of Nigeria. May have other names in different parts of Africa but the powdered pounded yam bought in the stores in the US are mostly called fufu by those who do not know the origin. Also in addition, yam is also used to treat infertility. We have Sweet Potatoes in some parts of Africa. For example in Nigeria we have Sweet potatoes in the north and south west.
I’VE ALWAYS THOUGHT THAT YAMS AND SWEET POTATOES WERE THE SAME … UNTILLLLLLLLLL I FOUND OUT THEY’RE NOT … NOT EVEN SIMILAR …
NOW I EAT ONLY SWEET POTATOES DAILY … SEVERAL OF THEM … THEY ARE MAGNIFICENT WITH BUTTER AND ALSO OLIVE OIL (BOTH WITH A BIT OF SALT)
IT’S MY FAVORITE VEGGIE …
White potatoes that are eaten with the skin on, in other words, you eat the skin, are quite healthy! They are higher in fiber and lower in sugar than sweet potatoes.
Not good if you are dieting or a diabetic
While white potatoes are lower in fat and sugar, sweet potatoes have fewer carbs and calories. And while sweet potatoes contain more vitamin A and vitamin C, white potatoes contain more protein and fiber.
Really, can you provide evidence please?
I think sweet potatoes are tastier. I’m not diabetic. White potatoes are sugar based! That is their chemical make up, ask a nutritionist! I had to follow a strict sugar free diet to get rid of a toxin & I couldn’t eat white potatoes at all, but I ate sweet potatoes like they were going out of style! Dilemma averted.
unless organic, I don’t eat potato skins. Pesticides, herbicides, toxins, etc. accumulate in the skin.
Another good article, clarifying my and many people’s confusion about sweet potatoes / yams!
Very informative, thank you.
Thanks for the education! Who knew? (Apparently, YOU!) I will be sharing this article to spread your wisdom. Thank you, again, for enlightening us!
Thankyou Very much! I’m Very Favorable to the consumption of All Potatoes! ( But it is Nice, to Know, the particulars!) Well Done. Joel
Your reports on my computor are in very print. What do I do to change that?
Hold CTRL down and tap + to enlarge or – to reduce the print size.
Yams have been used to help people with sickle cell anemia.
ALL potatoes of all and any color are loaded with starch that raises our blood sugars to terribly and unhealthy levels for everyone. In terms of 100-gram portions, white potatoes have 74% of their calories as starch which is very high. Sweet potatoes have 34% of their calories as starch which turns to blood sugar soon as the starch hits the amylase enzyme in our mouth. There’s no waiting for the Fibre Faerie Myth to have any impact on our glucose rising quickly as in double in 15 minutes and 5X higher in 30 minutes while we may still be eating. This has been the result of testing how starch becomes blood sugar almost instantly, all starch. Yams are the lowest in starch and only 20% of the calories are starch. But they’re a lot harder to find in a store.
If starches are so unhealthy, there are about a billion Chinese, okinowans and others who eat traditional diets of predominantly starches who never got that membership and live to 90+ healthfully.
Hi, just being a bit nit-picky but the picture of the yam you used is nagaimo (Chinese yam). But otherwise it’s an informative article, thank you!
As a nutritionist, I’d be interested in seeing your he science behind your comment about adding better to help convert beta carotene to VitaminA.
Red potatoes are much better for you than russets.
yams & sweet potatoes are mistaken for each other just like Buffalo and Bison….and crocodile and alligator
Buffalo and bison are not the same?
Well, there is the South African Water Buffalo and then we have the American Bison, commonly called Buffalo, but to a real culturist it is a Tatonka.
I’ve never confused a crocodile with an alligator. Two very distinct reptiles. Now, throw in a Caiman in the mix. A Caiman looks half way between a crocodile and an alligator. And could be confused with one of the others.
Yams are cheaper, very fibrous, don’t taste as well as sweet potatoes (which are my favorite).
I find that ‘ordinary’ potatoes, as part of the solanaceae family of vegetables, are very bad for my osteoarthritis. This group sadly also includes tomatoes.
Aren’t tomatoes a fruit?
And, by the way, peanut is a misnomer.
Nuts grow on trees. Peanuts are beans, by gum!
I am so glad that your article clarifies the difference between sweet potatoes and yams. As the daughter of a sweet potato grower——long before sweets became a trendy vegetable—- it has bothered me that the two names are confused with each other. One thing I would like to point out, however, is that even though sweet potatoes have their origin in Central and South America, the sweets we buy in the supermarkets across the country today likely come from California’s San Joaquin Valley, several southern states, and even New Jersey (hence, the Jersey sweet potato). Sweet potatoes are, indeed, a home-grown product.
I thought I new a lot about potatoes but I was very wrong, I didn’t know crap ,Thanks for the information!!
Dem white potatoes be racist!
LOL! 🙂
One thing I have read about white potatoes is if they are prepared and then refrigerated and reheated, it does something to the starch and it doesn’t raise a diabetics blood sugar near as much. someone should double check on this, because i wouldn’t want to make anyone sick.
You are correct. I believe the same is true for pasta. Healthier to eat in cold salads
Cooking then refrigerating potatoes or nightshade vegetables or beans, Just lessons the lectins if you do that. , but Dr Gundry says nothing helps wheat lesson those bad lectins from hurting your gut.
Well, there is the South African Water Buffalo and then we have the American Bison, commonly called Buffalo, but to a real culturist it is a Tatonka.
Thanks to all for the VERY helpful information. I am diabetic… have had 1 heart attack.. AND I’m OLD! I bet I will be eating more sweet potatoes in future though. 🙂
I did not know there was a difference between yams and sweet potatoes. Of course, I will be sneaking in the occasional “regular” potato though. As a “true American”… Don’t tell ME what to do!! lol
George