Purple Potatoes: Benefits, Nutrition, Recipes & Side Effects

Dr. Josh Axe · Free quiz

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Purple potatoes are regular potatoes, the same Solanum tuberosum you'd bake or mash, whose skin and often flesh are colored deep violet by anthocyanins, the family of plant pigments that also colors blueberries, and they're one of the most nourishing ways to eat a potato.1112 My rule of thumb for plants is that the deeper the color, the stronger the healing potential, and purple potatoes bear it out: in a two-week study in which each of 14 healthy adults tried both, a daily serving of cooked purple potatoes made their arteries more flexible, while white potatoes didn't.131

Potatoes get blamed for a lot, but what a potato does in your body depends on what comes along with its starch. A plain potato eaten on its own turns its starch into blood sugar quickly, while a purple potato eaten with its skin, after your vegetables and alongside protein, brings its own pigments, fiber and resistant starch to the meal.14815 Those go to work in your gut and your blood vessels, and that's where the research on purple potatoes lands, from more flexible arteries to a smaller insulin rise after meals.12 I've always believed in using food as medicine first, and purple potatoes show how a few small choices, the variety you buy, whether you keep the skin and what you eat it with, change what an everyday food does for you.16

If you came looking for purple sweet potatoes, you'll find them here too, though they come from a different plant altogether. Sweet potatoes belong to the morning glory family, potatoes to the nightshade family and true yams, ube among them, to a family of their own, so this page covers purple potatoes first and then gives purple sweet potatoes and ube their own section, with their own nutrition and research.9

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What are purple potatoes?

Cut a purple potato in half and you'll often find the color runs all the way through, sometimes solid violet, sometimes marbled with cream. Its pigments build up in the skin and the layers just beneath it, and in purple-fleshed varieties they fill the flesh too.11 The color comes from anthocyanins, mostly ones built on petunidin, and in purple potatoes these pigments often carry an extra phenolic acid attached to their sugars, which chemists call acylation.1118 That small difference makes them more stable than ordinary anthocyanins, which is one reason food makers are interested in them as natural colorings, and it changes how your body handles them, as the next sections explain.12

If you've wondered whether purple potatoes are natural, they're as natural as any potato. The potato itself began in the Andes of South America, where native varieties still come in a wide range of colors, with purple types rich in petunidin and red ones in a different pigment, pelargonidin.1518 The purple variety you'll see most often in the research, Purple Majesty, came out of Colorado's potato-breeding program as a naturally occurring variation.1 Where a potato grows matters for its color too: potatoes raised under long days and cool temperatures built about 2.5 times more anthocyanins than those grown under short days and heat.18

Names you'll see for purple potatoes

You'll find purple potatoes sold by variety name, and these are some you'll see in the research:

A short history of purple potatoes

Potatoes were first cultivated in the Andes, and from there they spread to more than 160 countries.15 The Andean farmers who domesticated them kept an enormous range of varieties, and when researchers analyzed 74 traditional varieties chosen from a collection of nearly 1,000, their total phenolics varied more than tenfold, from 1.12 to 12.37 milligrams per gram of dry weight.20 Farmers in Peru still grow native potatoes high in the mountains, including native varieties studied at 3,496 meters, about 11,500 feet, so the purple potatoes in your grocery store come from a very long line of colorful potatoes.21

Purple potato nutrition facts

Purple and white potatoes share the same basic nutrition, and the difference between them is in their plant compounds. In the arteries study on this page, the supplier's analysis gave the purple and white potatoes the same 154 calories, 34.8 grams of carbohydrate, 4 grams of protein and 2.1 grams of fiber in each 200-gram serving, but after boiling, the purple potatoes held 1,468.8 milligrams of total phenolics per kilogram against 227.8 for the white ones, more than six times as much, along with 1,445.1 milligrams of anthocyanins per kilogram, which the white potatoes lacked.1 That means a purple potato gives you all the nutrition of a white one, with its extra pigments and phenolics on top.

Darker flesh tends to mean more of these compounds, so it's worth looking for varieties that are purple all the way through, not just on the skin. When Canadian researchers compared four potatoes cooked with their skins, purple carried 234 milligrams of polyphenols per 100 grams of dry weight, red 190, yellow 108 and white 82.14 In a Polish study of eight varieties, the colored-flesh Vitelotte carried the most phenolic acids, 129.94 milligrams per 100 grams, and in another analysis, chlorogenic acid, the main phenolic acid in potatoes, made up 35% to 82% of the free phenolic acids in potatoes with white, yellow, red and purple flesh.1922

Calculated from USDA FoodData Central FDC ID 170093 (potatoes, baked, flesh and skin, without salt) at its medium-potato weight of 173 grams; % Daily Value uses FDA adult label values. USDA has no separate record for purple potatoes.3

Potatoes are a better source of vitamin C than most people realize, though cooking takes some of it: USDA lists 19.7 milligrams per 100 grams of raw potato against 9.6 milligrams once it's baked.233 Potassium is the mineral to notice, because it's a big part of what potatoes can do for your blood pressure, which the benefits below cover.

How purple potatoes work in your body

When you eat a purple potato, you're eating two things your body handles in very different ways: the violet pigments and phenolic acids packed into its skin and flesh, and the starch that makes it a potato. The pigments mostly don't reach your blood the way they went in, and that turns out to be part of how they help you.12

When 17 healthy men in Finland ate a yellow potato meal with and without an extract made from purple potatoes, the original anthocyanins never showed up in their blood or urine. What did appear were 28 smaller phenolic compounds in their urine and 14 in their blood, and the late timing of those peaks pointed to the colon, where gut bacteria break the pigments down.24 The researchers concluded that these acylated anthocyanins are more bioavailable than earlier studies had suggested, once you count everything your gut makes from them. So your gut bacteria do much of the work here, turning the pigment you can see into compounds that circulate through your body.

The starch side follows a similar path. Some of a potato's starch escapes digestion in your small intestine and travels on to your colon, where bacteria ferment it into short-chain fatty acids such as butyrate, the fuel your colon cells prefer.25 That's why I tell people to cook their potatoes, let them cool and eat them later that day or the next. The starch in sweet potatoes, white potatoes, purple sweet potatoes, any type of potato, is fantastic, and I consider this resistant starch the number one starch for supporting butyrate production.6

Your blood vessels are the other place this shows up. Researchers think anthocyanins help the inner lining of your arteries make nitric oxide, the molecule that lets them relax, and chlorogenic acid may add to that effect, both proposed explanations for why purple potatoes made arteries more flexible in people.1

From your plate to your arteries, a purple potato works in five steps.

Because so much of this happens in your gut and the lining of your arteries, a purple potato does the most for you as a regular part of your meals, eaten with its skin.

Purple potato benefits

Purple sweet potatoes: what they are and what they do for you

If you've ever cut into a sweet potato and found deep violet inside, you've met this one. The variety sold as Okinawan sweet potato is purple-fleshed and is a primary commercial crop in Hawaiʻi, and in Japan, breeders developed Ayamurasaki, a purple-fleshed sweet potato with a high anthocyanin content, along with several other purple varieties.383918 Their color can vary a lot, with sixfold differences in anthocyanin content recorded among purple-fleshed sweet potatoes.18 Sweet potatoes in general were eaten in large amounts in the traditional diet of Okinawa, the Japanese islands known for their long-lived people, a diet researchers describe as low in calories yet rich in antioxidants and other plant compounds.41 Our guide to the Okinawa diet and our guide to the Blue Zones tell more of that story.

Purple sweet potato nutrition

USDA doesn't list purple sweet potatoes separately, so the closest figures come from its general sweet potato record: a medium sweet potato baked in its skin (114 grams) has about 103 calories, 23.6 grams of carbohydrate, 3.8 grams of fiber, 2.3 grams of protein and 542 milligrams of potassium.42 That record's large amount of vitamin A comes from beta-carotene, the pigment that makes orange sweet potatoes orange, so it doesn't tell you what a purple-fleshed sweet potato carries.42 I group sweet potatoes with the starchy vegetables that, unlike refined starches, release their glucose slowly while delivering antioxidants.13

Purple sweet potato benefits

Purple sweet potatoes look after your liver, and that's where most of their human research has focused. In a placebo-controlled trial in Japan, 38 men aged 30 to 60 whose liver enzymes ran borderline-high drank two bottles a day of a beverage made from purple sweet potato, about 400 milligrams of anthocyanins in all, for 8 weeks. By week 8, their GGT, a liver enzyme that rises when the liver is under strain, was 27.9 units per liter lower than in the men drinking a placebo, and two other liver enzymes, AST and ALT, also ran lower in the purple sweet potato group.10 In a pilot trial of 40 healthy adults aged 41 to 69 with borderline-high liver enzymes, three bottles a day of the same kind of drink lowered GGT, AST and ALT compared with placebo by day 43, with no clinically relevant changes in other blood tests; some of its authors work for a Japanese food company.40

Blood pressure may benefit too. In a 4-week study of 20 adults with excess weight, raised blood pressure and raised liver enzymes, everyone drank two cartons a day and knew what they were drinking, with no comparison group. Their systolic blood pressure was lower after the 4 weeks than before they started, then rose again after they stopped.39 Your body takes up these pigments, too: an acylated anthocyanin from a purple sweet potato drink showed up in the urine of 87 healthy volunteers 2 hours after they drank it.43

Sweet potatoes in Chinese medicine

In traditional Chinese medicine, sweet potatoes, yams and squash are very nourishing to the spleen, which in that tradition really means your digestion, and I consider them very good for the thyroid as well.44 Purple sweet potatoes are the same plant as orange ones, so they belong in that group too.39 Chinese medicine also has a principle that in early fall you eat more orange and yellow foods, such as squash, pumpkin and sweet potatoes, which are naturally sweet but don't have to tax your pancreas and blood sugar.45 In the fall, I like to season sweet potatoes, pumpkin and squash with pumpkin pie spice, cinnamon or ginger.45

That protein comes from bone broth or collagen protein and a healthy plant protein, with about half a teaspoon of pumpkin pie spice, which brings cinnamon and ginger.44 A cooked purple sweet potato works the same way in that smoothie and turns it a deep violet. When people struggle with constipation around the holidays, I'll often use half a sweet potato in a morning smoothie in place of fruit, with flax meal, a vanilla protein powder and a whole teaspoon of pumpkin pie spice, and it's really good for your bowel movements.45

Is ube the same as a purple sweet potato?

No. Ube is a purple yam, Dioscorea alata, from the yam family, while purple sweet potatoes are sweet potatoes from the morning glory family.469 Also called water yam or purple yam, it's a traditional food and medicine across Asia and the Pacific Islands, used for weakness, inflammation, menstrual complaints, wounds and digestive troubles, and its saponins and anthocyanins are now being studied in the lab.46

Yams have also been used traditionally for menopausal symptoms, and one study put that to a test. In a before-and-after study in Taiwan, 22 postmenopausal women replaced the rice in two of their three daily meals with 390 grams of yam of the same species as ube for 30 days, and their estrone rose 26%, their sex hormone binding globulin rose 9.5%, their cholesterol fell 5.9% and a urinary marker of oxidative stress dropped 42%, while in a similar study of 19 women who ate sweet potato instead, the same hormone measures didn't change.47 USDA's general yam record gives a cup of cooked yam (136 grams) about 158 calories, 5.3 grams of fiber and 911 milligrams of potassium.48 Our guide to yams covers ube in more depth.

Are purple potatoes a nightshade?

Nightshade vegetables make their own natural defense compounds, called glycoalkaloids, and researchers have described how these can disrupt the gut lining and may stir up mast cells in the gut wall, one proposed reason some people with irritable bowel syndrome or inflammatory bowel disease feel worse after eating nightshades.17 With autoimmune disease, I don't think nightshades bother everybody, but they do bother some people,50 and people with gut trouble vary in the same way.

Your own body is the best guide to which group you're in. If joint pain, bloating or an autoimmune flare keeps coming back, set tomatoes, peppers and eggplant aside for three weeks, and potatoes too if you suspect them, then bring them back one food at a time, watching for three days for stiffness, puffiness or gut symptoms before you add the next.49 Purple sweet potatoes are a good swap while you test, since they aren't nightshades.9

How much purple potato should you eat?

A purple potato works best as the starch on your plate, beside your protein and vegetables. A medium potato is a realistic serving, in line with the 150 grams a day in the DNA-damage study and the 200 grams a day in the arteries study, and it brings about 37 grams of carbohydrate.413 Put your vegetables and protein on your fork first and the potato last, the meal order my blood sugar protocol starts with, since it keeps carbs with the meal instead of eaten on their own.8

If you train hard, a purple potato with some protein is one of the simplest whole-food meals for refueling after a long workout, and it brings potassium along with its carbohydrate.3 And when you shop, look for the deepest color you can find. White potatoes, yams and sweet potatoes are all on my list of foods to eat, and my advice is to buy organic when possible; our guide to organic foods explains why.51

How to cook purple potatoes so they keep their color

Purple potatoes cook just like any other potato, so you can swap them into almost any recipe, and their mild, slightly earthy flavor takes well to garlic, herbs and good oils.

Ways to use purple potatoes

I recommend cutting artificial food dyes out of your diet altogether, so natural color from foods like these is a welcome swap in your kitchen; our guide to Red Dye No. 3 explains the concern with one of those dyes.5112

Cooking tips that keep the color

• Keep the skin on. The skin and the layers just under it hold a concentrated share of the pigment, and unpeeled potatoes keep more of their phenolics through cooking.111
• Steam or microwave when you can. In a study of purple-fleshed potatoes, steaming and microwaving kept most of their health-promoting compounds, while stir-frying kept only slight amounts.7 In another, on a purple variety called Purple Pelisse, steaming and boiling the potatoes sealed in a vacuum bag kept their antioxidant activity, while plain boiling lowered it.52
• Try the air fryer. In the first of those studies, air-frying raised one antioxidant reading by 30.52%, and it gives you crisp potatoes without a pot of oil.7 Our guide to the air fryer has more ideas.
• Skip the deep fryer. The Anti-Inflammatory Reset cuts fried food and seed oils and has you cook with olive oil, avocado oil, ghee or coconut oil instead.49
• Expect the shade to shift. A squeeze of lemon or a splash of vinegar can change the color a little, since pH changes the color of these pigments.18

How to buy and store purple potatoes

Choose firm potatoes with smooth, unwrinkled skin and no soft spots, green patches or sprouts, and keep them somewhere cool and dark, since light is what turns potatoes green (the safety section explains why that matters). You'll find them at many grocery stores and farmers markets, sometimes sold in mixed bags with red and yellow potatoes.

Purple potato recipes

Here are three classic purple potato recipes, written out in full and cooked the way I recommend, in extra virgin olive oil, avocado oil or ghee, with no deep frying.49 At Thanksgiving, the garlic mash is an easy way to bring a violet dish to the holiday table, and our Thanksgiving side dishes have more ideas.

Roasted purple potatoes with lemon, Dijon and thyme dressing

Roasting brings out the purple potato's nutty flavor, and a bright lemon-Dijon dressing finishes them while they're still warm.

Garlic purple mashed potatoes

Steaming kept more of a purple potato's antioxidant activity than plain boiling in one study, and ghee with warm bone broth makes the mash rich and creamy without heavy cream.52

Oven-roasted purple potato fries

These get their crunch from a hot oven or an air fryer instead of a deep fryer.

More purple potato and purple sweet potato ideas

• Cooked-and-cooled purple potato salad: Steam cubed purple potatoes until just tender, refrigerate them overnight, then toss with extra virgin olive oil, apple cider vinegar, Dijon mustard, diced red onion and celery, fresh dill and chopped hard-boiled eggs.
• Purple sweet potato breakfast smoothie: Blend about a cup of cooked purple sweet potato with coconut milk or water, bone broth protein or collagen protein, a plant protein and half a teaspoon of pumpkin pie spice, the smoothie described above.
• Spiced purple sweet potato mash: Mash baked purple sweet potatoes with a little ghee or coconut milk, cinnamon and fresh ginger for a holiday side.
• Purple potato and leek soup: Sauté sliced leeks in ghee, add cubed purple potatoes and chicken bone broth, simmer until tender and blend until smooth.

Purple potato side effects and who should be careful

Purple potatoes are a safe everyday food for nearly everyone, and the cautions are the same as for any potato.

Interaction check: Low. The one point to keep in mind is potassium: a medium baked potato with its skin carries 926 milligrams, and when your kidneys can't clear potassium well, because of chronic kidney disease or medicines such as ACE inhibitors or potassium-sparing diuretics, even ordinary food amounts can push it too high.330 If you've been told to limit potassium, keep your potato portions within the plan your doctor gave you; our guide to hyperkalemia explains the warning signs.

Green or sprouted potatoes

Potatoes make solanine and chaconine, natural glycoalkaloids that defend the plant, and light raises those compounds in the skin at the same time as it turns the skin green.53 The peel holds 3 to 10 times the amount of glycoalkaloids in the flesh, and peeling removes 25% to 75% of them.53 At high enough amounts, from about 1 milligram per kilogram of body weight in a day, the European Food Safety Authority found they can cause nausea, vomiting and diarrhea, though it found no evidence of health problems from eating potatoes regularly over the long term.53 In a dosing study, volunteers had no body-wide effects at up to 1.25 milligrams per kilogram, and one person at that top dose vomited a few hours later.54 So store your potatoes somewhere cool and dark, cut away any green patches, eyes and sprouts, skip potatoes that have turned green over much of their skin, and throw out any potato that tastes bitter or makes your mouth burn.53

Nightshade sensitivity. If joint pain, gut symptoms or an autoimmune condition is part of your picture, start with the three-week trial in the nightshade section above.

Purple sweet potatoes and ube. We found no harms specific to purple sweet potatoes or ube at food amounts, and in the purple sweet potato drink trials, people had no clinically relevant changes in their blood or urine safety tests.4039

The bottom line

Purple potatoes: frequently asked questions

References

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44. Axe J. How to Heal Hypothyroidism and Hashimoto's Naturally. The Dr. Josh Axe Show. 2024 (sweet potatoes, yams and squash in Chinese medicine, at 42:17; the sweet potato breakfast smoothie, at 42:28; YouTube https://www.youtube.com/watch?v=OpI4SSyOQ6c&t=2537s).
45. Axe J. Top 5 Holiday Superfoods You Didn't Know You Needed. The Dr. Josh Axe Show. 2024 (orange and yellow foods in early fall in Chinese medicine, and seasoning with pumpkin pie spice, cinnamon and ginger, at 8:15; sweet potato smoothies for holiday constipation, at 10:04; YouTube https://www.youtube.com/watch?v=ppj8vUGgLNI&t=495s).
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49. Axe J. The Anti-Inflammatory Reset: The 30-Day Healing Protocol. DrAxe.com protocol. 2026 (Phase 1, Remove: cut fried food and seed oils and cook with olive oil, avocado oil, ghee or coconut oil; Phase 2, Cool: eat the rainbow, at least five colors of plants a day; Phase 4, Maintain: reintroduce one food at a time, watching three days; FAQ, "What about nightshades?", p. 26).
50. Axe J. Top 15 Remedies to Reverse Autoimmune Disease. The Dr. Axe Show. July 29, 2024 (at 15:26; YouTube https://www.youtube.com/watch?v=L7y0UzQPJF0&t=926s).
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Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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