Sweet potatoes are one of the healthiest known vegetables.
Toxins in Sweet Potatoes?
Doctor's Note
Check out these videos to learn more about sweet potatoes:
Anti-Cancer Potential of Sweet Potato Proteins
The Best Way to Cook Sweet Potatoes
And check out my other “HHH” videos (Harmful, Harmless, or Helpful?) – listed below the post.
For more context, please check out my associated blog post: Soymilk: shake it up!
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So are you saying that it is bad to eat potato skins? I thought they had healthy nutrients?
-thanks, Dave
Hi Dave,
You’re better off not eating the skins. Although they may contain nutrients, potato skins are still not worth eating due to their toxic properties. Peel the skin, and try to occasionally substitute white potatoes with sweet potatoes to boost your nutrient intake.
I hope this helps!
Alexandra
Doctor, Do you recommend that we peel our sweet potatoes as well?
No need!
Two questions: 1) What about white sweet potatoes? Mayo clinic was mentioning only orange sweet potatoes, which I don’t like. But I like white sweet potatoes a lot!
http://www.mayoclinic.com/health/health-foods/MY01108&slide=9
2) What about sweet potato skin? A skin of regular potato is harmful, is the skin of sweet potato OK?
I wonder the same thing. There are many different versions of sweet potatoes such as the purple sweet potato, the Japanese sweet potato, Okinawan sweet potato, and as you mentioned white sweet potatoes along with a few others. I’m not so much of a fan of the orange/reddish ones either.
Also wondering if other sweet potato varieties are just as good.
Could you clarify what you mean by white potatoes? Would this include russets, yukon golds, etc.?
Thanks a lot! I love your website :)
Yep–even purple potatoes! (though they may have special properties).
I get to eat this sweet healthy food. Woot!
Here’s some new and different sweet potato recipes I found…some even using Dr. G’s favorite spices.
http://www.ncsweetpotatoes.com
Now that we know we can eat nuts (http://nutritionfacts.org/video/nuts-and-obesity-the-weight-of-evidence/) and nut butters (http://nutritionfacts.org/video/testing-the-pistachio-principle/) without fear of weight gain we can use them to flavour this surprisingly amazing stew which just so happens to contain one of the healthiest vegetables
(http://nutritionfacts.org/video/toxins-in-sweet-potatoes/).
Peanut/Almond Butter Barley Stew
-1 ½ cups barley*
-3 cups water/homemade vegetable broth
-1 red onion, chopped (http://nutritionfacts.org/video/carrots-vs-baby-carrots-2/)
-2 cloves garlic, minced (http://nutritionfacts.org/video/1-anticancer-vegetable/)
-½ inch piece of fresh gingerroot, minced
-4 carrots, diced
-1 large sweet potato, cubed
-jar strained tomatoes
-1 tsp cumin
-pinch cayenne pepper
-2 tbsp unsalted peanut or almond butter
-chopped peanuts/almonds for garnish
-sea salt and black pepper to taste
Place all ingredients except peanut butter, peanuts, and salt into a large soup pot. Cook for 40 minutes until barley almost cooked. Add peanut butter and cook until it has melted and heated. Season to taste with sea salt and black pepper. Serve garnished with peanuts.
*If sensitive to gluten substitute with buckwheat
~Complements of lovestobevegan
Sounds yummy! Thank you for sharing. Anyone else have any recipes to share?
What about yams? I see sweet potatoes and yams used interchangeably in the store often. Following the rule of more colorful usually = better, I’d pick a garnet yam over the less colorful sweet potato. But which is actually better?
We eat whole food/plant based in our family, and have a young child, so I’m conscious of what we eat. But the sweet potato/yam question is still unclear to me. Thanks!
I would not worry about this, because both of these foods are quite healthy. Usually it is the case that the more colorful foods have more antioxidants but these foods are both very healthy so its not much concern.
I have found an interesting fact about sweet potato :
http://abstracts.acs.org/chem/244nm/program/view.php?obj_id=143706&terms=
I always like to check sources. But in this case, there’s an apparent contradiction. Salmon is also in their top ten healthiest foods list, so by the exact same logic, salmon is also great for you! But I thought you were against all fish consumption (mercury, PCB’s, heterocyclic amines, etc.)?
When it comes to peeling the white potatoes, does this apply also to organic potatoes?
Dear Dr. Greger,
I was wondering about the different types of sweet potato. In my local supermarket they sometimes have the ones with orange flesh but more often the red ones with white flesh, though they’re sold under the same name.
Both ok, or just the orange ones?
Thank you,
Coen (from the netherlands)
I recently read that white potatoes contain antinutrients. Is this also true for yams?
All foods contain antinutrients. Eggs and Dairy inhibit Iron, so does soy protein and phytic acid. Calcium also inhibits Iron absorption, as well as Zinc. However, adequate intake of the recommended daily value is likely to be enough to counter any anti-nutritious effects of plant foods. If you’re really worried, the recommended intake for men is 16 mg a day – accounting for the absorption rate of non-heme iron – so just eat a bit more than that. The greatest concern with potatoes is that the skin is rich in polyphenols. Most of these polyphenols are incredibly good for human health, but some of them have the added side-effect of inhibiting Iron absorption by as much as 99%. Catechins in tea and gallic acid in berries are the most potent, and are present in sweet and white potatoes – and yams. This study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5224543/ showed a neutral effect from the polyphenols in sweet potato because they are also rich in Vitamin C which counteracted most of the polyphenols.
However, there is no reason to avoid Sweet Potatoes or Yams – or even White Potatoes, Dr Greger is just overreacting – just eat them with low-polyphenol-high-vitamin C foods that will help untangle the Iron from the grasp of the sweet potato polyphenols.
Low Polyphenol foods would include broccoli, cruciferous vegetables and peeled fruits.
Good news, however, is that the current perception of polyphenols as inhibitory to iron absorption is being eroded by the revelation that very few of these studies obey the necessary criteria to be considered valid. This analysis showed that polyphenol-rich beans and grains may actually have better Iron absorption than their lighter-coloured high-phytate equivalents. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5998341/
Can it be harmful to sprout sweet potatoes in a preschool classroom?
I had sweet potato lady week and since then I am having some symptoms related to brain fog, confusion, irritability. I am also feeling more calmer but overall feeling irritated and hyper. Please advise.
Please tell me about Murasaki Sweet Potatoes, they have purple skin and white flesh – are these good for you? If you juice them for G-tube feeding, should the skin be left on? What variety of sweet potato are the purple ones the Dr. recommends?
Thank you for your question. The purple sweet potato that has been associated with health benefits is the Okinawan Sweet Potato. The diet of the Okinawan’s in Japan can consist of 70% purple sweet potato and they seem to be one of the healthiest populations in the world.
https://nutritionfacts.org/video/the-okinawa-diet-living-to-100/
Juicing with the skin on is fine
So apparently the skin on sweet potatoes is fine/safer? I don’t eat regular potatoes all that much (not a fan). Just wondering though about the skin on a sweet potato safe or not?
I did a thorough search in Medline looking for studies specifically zeroing in on the safety of sweet potato skins and found that most studies focused on white potatoes. It appears the type of pesticides used on sweet v white potatoes and while washing can be effective in eliminating the pesticides fairly well Consider this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3907644/
Effect of handling and processing on pesticide residues in food- a review
Washing with tap water or aqueous solutions of acetic acid and/or NaCl, and blanching or frying of potatoes also removed most residues.
I would suggest that washing might be more effective with sweet potatoes since the often do not have the additional “knobs’ that white pototoes have making thorough washing less effective. I was able to track down this study which may make you feel better about eating sweet potato skins than white:
http://www.whatsonmyfood.org/food.jsp?food=PO/ You can compare the pesticides found with analysis of both sweet and white potatoes with 35 pesticides identified in the white, only 19 in the sweet and of those 6 known carcinogenic pesticides identified for white, only 3, in much less concentration in sweet.
Carcinogenic of course sounds alarming, but I found many research studies validating the benefit of the fiber found in sweet potato skins which also should be considered. I can’t give you a yes or no answer, but these studies may help you determine whether to pell or sweet potatoes or not.