Sweet potatoes: pros and cons, GI, how to cook them
I have Portugal to thank for the fact that today I know and appreciate sweet potatoes, known locally as batata doce: one of the country’s gastronomic icons, they are found in local markets, on the menus of trattorias and certainly in bakeries: in fact, they are not only sold as an ingredient in various desserts, but also simply baked. Uma batata doce assada, por favor!
And in the town of Aljezur (not far from where I live) they cultivate the small pear-shaped ones, with purple skin and incredibly yellow flesh; during the harvest period they organize very lively festivals, just like in Anguillara Veneta, in Calimera or in Frigole in Italy.
In European countries they are known as batata or yams or sugar potatoes, or also American potatoes, given that their origin is overseas, thanks to the famous navigator and explorer Christopher Columbus: who imported them from Latin America.
In the past, sweet potatoes could only be found in ethnic shops and markets, but since they are also grown locally (in Italy the Veneto region and Padua in particular are the largest producers), it is now easy to find them even in traditional local markets.
The pros of sweet potatoes
I like sweet potatoes because they are not only delicious, but they are a powerhouse of nutrients, and they have beautiful, intense colors (read more about the benefits of eating a rainbow here), from bright orange to dark purple: since we also eat with our eyes, sweet potatoes help to brighten up healthy dishes.
They are also very versatile: you can use them in a thousand ways, from soups to main courses, from side dishes to desserts (you must try this sweet potato nice cream before it’s too cold).
But the real reason I wanted to dedicate an article to them is that it is a resilient plant: despite its extreme sweetness, it is really tough underneath; it doesn’t need too much water or special care.
And as if that were not enough, it provides a pleasant source of sustenance for a large number of inhabitants of the least hospitable places on the planet.
On the other hand, sweet potato is so off-beat that it was once chosen for experiments on NASA missions because of it’s drought resistance and excellent nutritional profile.
The staple food of the world’s poorest people is a superfood
Here’s another reason why I like the sweet potato: ever since the Western countries became aware of its existence, not a day goes by without something amazing being published about it, such as it being the new superfood[2,3]: in addition to being, as mentioned, a valuable source of nutrition, it has great potential for treating diabetes, cancer, liver disease, obesity, and various inflammatory conditions.
Here is how the Oxford Dictionary defines the term superfood: “a food rich in nutrients and considered particularly beneficial to health and well-being”.
Although its valuable therapeutic properties for the treatment of various diseases require long-term clinical studies to be approved by regulatory bodies, sweet potatoes can be considered a super food in its own right due to its high amount of dietary fiber and other bioactive carbohydrates; vitamins, especially vitamin C, B1 (thiamine), B5 (pantothenic acid) and B6 (pyridoxine); mineral salts (such as magnesium, calcium, iron, potassium, manganese and copper); polyphenols (TPCs); and a vibrant antioxidant activity.
So let’s sing the praises of the sweet potato:
– Just one 100-gram sweet potato can provide 400 percent of the daily value of vitamin A, making it a valuable ally for healthy eyes, immune system, kidneys and, last but not least, the heart;
– Rich in antioxidants and polyphenols, orange sweet potatoes contain high levels of beta-carotene; this powerful antioxidant helps improve overall health by boosting the body’s defenses while also revitalizing the gut microbiota.
Those with purple flesh, on the other hand, are rich in anthocyanins, which help fight inflammation and prevent colon cancer.
– Sweet potatoes are even useful against aging, thanks to the antioxidant molecules they contain;
– They are rich in dietary fiber, both soluble and insoluble (resistant starch), which automatically makes them perfect prebiotics.
Differences Between Potatoes and Sweet Potatoes
Sweet potatoes (Ipomoea batatas), despite their name (potato), are actually different in both family and characteristics from the potato (Solanum tuberosum).
– They are actually part of the Convolvulaceae family, which is distinct from the Solanaceae (also called Nightshade) family, to which regular potatoes belong.
The Solanaceae group is large and includes some very common foods (eggplant, tomatoes, peppers, and others), the consumption of which is thought to cause severe inflammation even in sensitive people.
It has not been scientifically proven that they can also cause problems in healthy people; however, nowadays many people in the world replace them with sweet potatoes: not only is it suspected that they can cause inflammation, but more importantly, sweet potatoes, on the contrary, have anti-inflammatory properties.
– Sweet potatoes, which do not belong to the Solanaceae family, can also be eaten raw, although it is not advisable to do so with regular potatoes: you would be unnecessarily absorbing (raw potatoes don’t taste good) solanine, a neurotoxin that accumulates in various organs, for up to sixty days.
– They have about the same amount of carbohydrates: out of 100g, about 29g for potatoes and 26g for sweet potatoes.
The real difference lies in their composition: the carbohydrates in regular potatoes are mainly starch (24g), while in sweet potatoes starch is present for 16g; sugar abounds with 5g in sweet potatoes compared to about 1.5g in regular potatoes… as you might have guessed!
Fiber levels are not much different, although batatas have more: 3.9g versus 3.1g.
– The really important difference lies in the glycemic index levels: boiled regular potatoes belong to the group of foods with the highest glycemic index, namely 85; boiled sweet potatoes, on the other hand, have a GI of 63, placing them in the medium GI group.
Can diabetics eat sweet potatoes?
From what we have just learned, it is clear that nutritionists prefer it to the regular potato, precisely because of its higher fiber content and lower glycemic index. Even more surprising is the fact that in scientific circles it is even considered by some researchers as a substitute for drugs, since it is considered effective in the treatment of hyperglycemia: its pharmacological activity is considered superior to that of Diabinese (a drug commonly used for diabetes mellitus in adults).
It should be mentioned, however, that to date there is insufficient scientific evidence in the literature on the use of sweet potato as a treatment for type 2 diabetes mellitus; however, there is reasonable confirmation from animal models and clinical trials, including randomized controlled trials (RCTs), which suggest that sweet potato may help control blood glucose levels; furthermore, that sweet potato nutraceuticals may be useful in the management of type 2 diabetes mellitus[8,9,10].
Thus, there is hope for further important findings in the face of a problem (diabetes) that has become a real scourge in recent decades.
Therefore, it is perfectly fine to be your own doctor, but if you have diabetes, always consult your doctor before “self-curing” with sweet potatoes.
– The first is certainly their price; while they are the food of many poor nations, in Europe they cost about 50 percent more than regular potatoes. As always, it’s a matter of supply and demand, as sweet potatoes are now a niche product.
– Overeating is all too common with superfoods, especially when they are as good as sweet potatoes. And it is precisely because they are loaded with nutrients that one must be cautious in their consumption; the high amount of potassium could lead to hyperkalemia or potassium toxicity, even causing you a heart attack. Moderation is always a magical word!
– Similarly, if you suffer from kidney stones or simply have kidney problems, it is best not to exceed the daily intake, i.e. no more than one sweet potato a day; beyond that, its rich oxalate content could increase the work of the kidneys.
– Similarly, exceeding the amount of sweet potatoes, especially if you are also taking vitamin A supplements, could create the basis for hypervitaminosis; this can be avoided by staying below 300 mg daily.
However, rest assured that it is very unlikely that you will approach this threshold with a normal diet: 100 g of sweet potatoes contain 0.7 mg of vitamin A.
In any case, to avoid various minor ailments such as headaches and yellowish hands and feet, I recommend that you eat no more than 1 medium-sized sweet potato per day.
How to clean sweet potatoes
If they’re organic, it’s best to eat them with the skin on to get all the nutrients and lower the glycemic index even more.
Use an ordinary potato brush to remove dirt or other impurities from the surface; wash under running water and you are ready to use them in recipes.
How to cook sweet potatoes
– To bake whole: poke a few holes in the flesh with a fork and bake at 220 degrees for about 40 minutes (the long baking time makes it ideal to combine the session for baked quince and/or chestnuts and/or bread or pizza – the goal is always to save energy!)
When they are soft, serve them as they are, or cut them vertically and stuff them with whatever you like: cheese, vegetables, legumes, eggs, or… chocolate and/or dates and cinnamon.
– To make baked sweet potato fries: cut them into sticks, or slice them horizontally into slices or cubes, then season with evo oil, salt, pepper and your favorite spices (curry and paprika, with a squeeze of lemon, are unbeatable for me).
At 200 degrees, about 15 minutes (20 for the cubes) would be enough.
– Steamed in a pressure cooker: if you want them whole, you’ll need to cook them for 15 to 30 minutes, depending on their size; otherwise, if you cut them into cubes, you’ll only need about 8 to 10 minutes from the time the pot goes under pressure.
In conclusion, add sweet potatoes to your diet with this guide in mind: you will certainly enrich your life with a humble superfood.
Enjoy your meal and have a good revolution!
1) Hoff JE, Howe JM, Mitchell CA (1982) Nutritional and cultural aspects of plant species selection for a controlled ecological life support system. NASA Contractor Rep. 166324. Moffett Field, Cali. National Aeronautics and Space Administration, USA
2) Mohanraj R, Sivasankar S (2014) Sweet potato (Ipomoea batatas (L.) Lam)—a valuable medicinal food: a review. J Med Food 17:733–741
3) Wang S, Nie S, Zhu F (2016) Chemical constituents and health effects of sweet potato. Food Res Int 89:90–116
4) Yuxin Qin, Nenad Naumovski, Chaminda Senaka Ranadheera, Nathan M. D’Cunha,
Nutrition-related health outcomes of sweet potato (Ipomoea batatas) consumption: A systematic review, Food Bioscience, Volume 50, Part B, 2022, 102208, ISSN 2212-4292.
5) Loncaric, Ante & Nedic, Nela & Pilizota, Vlasta. (2016). Sweet potato a “Superfood”.
6) Naomi R, Bahari H, Yazid MD, Othman F, Zakaria ZA, Hussain MK. Potential Effects of Sweet Potato (Ipomoea batatas) in Hyperglycemia and Dyslipidemia—A Systematic Review in Diabetic Retinopathy Context. International Journal of Molecular Sciences. 2021; 22(19):10816
7) Ooi CP, Loke SC. Sweet potato for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2013;2013(9):CD009128. Published 2013 Sep 3. doi:10.1002/14651858.CD009128.pub3
8) Omodamiro, O.; Omodamiro, R. Evaluation of Hypoglycemic and Hypolipidemic Potentials of Sweet Potato on a Wistar Albino Rat. Am. J. Adv. Drug Deliv. 2018, 6.
9) Shih, C.K.; Chen, C.M.; Varga, V.; Shih, L.C.; Chen, P.R.; Lo, S.F.; Shyur, L.F.; Li, S.C. White sweet potato ameliorates hyperglycemia and regenerates pancreatic islets in diabetic mice. Food Nutr. Res. 2020, 64, 1–11
10) Pal, S.; Gautam, S.; Mishra, A.; Maurya, R.; Srivastava, A.K. Antihyperglycemic and Antidyslipidemic Potential of Ipomoea Batatas Leaves in Validated Diabetic Animal Models. Int. J. Pharm. Pharm. Sci. 2015, 7, 176–186