Purple and blue potatoes are the healthiest varieties overall, packing two to three times the antioxidant capacity of white-fleshed potatoes. But the full answer depends on what you’re optimizing for. If you want the most vitamin A, a sweet potato wins by a landslide. If you want the most iron and B6, a russet actually beats a red potato. And how you cook and serve any potato matters almost as much as which one you pick.
Purple Potatoes Lead in Antioxidants
Pigmented potatoes, including purple, blue, and deep red varieties, contain acylated anthocyanins, the same protective plant compounds found in blueberries and red cabbage. These pigments give purple potatoes two to three times the antioxidant potential of white-fleshed varieties. Red potatoes contain a different set of anthocyanins than purple ones, but both outperform standard white or yellow potatoes on antioxidant measures.
The practical takeaway: the deeper the color runs through the flesh (not just the skin), the more antioxidant value you’re getting. A potato with purple skin but white flesh won’t deliver nearly the same benefit as one that’s purple all the way through.
Russets Win on Iron and B Vitamins
If antioxidants aren’t your main concern, russet potatoes have a surprisingly strong nutritional profile. A baked russet (about 300 grams with skin) provides 62% of your daily vitamin B6 and 18% of your daily iron. A same-size baked red potato delivers only 37% of daily B6 and 12% of daily iron. Russets also edge out red potatoes slightly on magnesium, providing 21% of the daily value compared to 20%.
Both varieties are excellent sources of potassium, which is concentrated in the skin. Dried potato skin is roughly 52% fiber by weight, so eating the skin of any variety adds meaningful fiber and minerals that you’d otherwise throw away.
Sweet Potatoes Are in a Different League for Vitamin A
Orange-fleshed sweet potatoes provide 107% of your daily vitamin A in just 100 grams. Regular white potatoes provide 0.1%. That’s not a rounding error; it’s a completely different food when it comes to this one nutrient. The orange color comes from beta-carotene, which your body converts to vitamin A.
Beyond vitamin A, though, sweet potatoes and white potatoes are remarkably similar in calories, protein, and carbohydrates. White potatoes actually provide more potassium. So unless you specifically need more vitamin A in your diet (and many people do), a regular potato isn’t necessarily the lesser choice.
Blood Sugar Varies Wildly by Variety and Prep
Potatoes have a reputation for spiking blood sugar, but the glycemic index of potato products ranges from as low as 23 to as high as 144 depending on variety and cooking method. That’s an enormous spread, wider than almost any other single food.
A few patterns hold up across studies. Mashing potatoes consistently raises their glycemic impact, with mashed potatoes scoring between 74 and 97 on the glycemic index (glucose scale). Baking tends to fall in the mid-range, around 48 to 76 depending on the variety. Boiled potatoes vary the most: a boiled red potato served hot scored 89 in one study, but the same potato served cold dropped to 56.
That cold potato effect is real and significant. When cooked potatoes cool down, some of their starch converts into resistant starch, a form your body can’t fully digest. This means less blood sugar impact and more food for beneficial gut bacteria. Russet potatoes contain about 3.1 grams of resistant starch per 100 grams when freshly cooked, rising to 4.3 grams after chilling overnight. Yellow potatoes nearly double from 1.4 to 2.5 grams. Cooking potatoes a day ahead and refrigerating them overnight is the simplest way to lower their glycemic impact.
Potatoes Keep You Full Longer Than Almost Anything
One underappreciated advantage of potatoes is how satisfying they are. On the satiety index, which measures how full foods keep you relative to white bread (scored at 100%), boiled or baked potatoes scored 323%, the highest of any food tested. For comparison, french fries scored only 116%. The difference comes down to processing: a whole boiled potato digests slowly and stretches the stomach, while frying concentrates calories and strips away that effect.
If you’re trying to eat less without feeling hungry, a plain boiled potato is one of the most effective foods available. This is true regardless of variety.
How to Get the Most From Any Potato
No single potato variety is best across every nutritional dimension. But you can stack the advantages:
- For antioxidants: Choose purple or blue varieties with pigment throughout the flesh, not just the skin.
- For vitamin A: Orange-fleshed sweet potatoes are unmatched.
- For iron and B6: Russets outperform red and yellow varieties.
- For blood sugar control: Cook any variety ahead of time and refrigerate overnight before eating. Avoid mashing.
- For fiber and potassium: Eat the skin regardless of variety.
The least healthy potato is not a variety. It’s a preparation method. Frying reduces satiety, adds calories, and in some studies barely changes the glycemic index compared to baking. The biggest nutritional upgrade most people can make isn’t switching from yellow to purple. It’s switching from fried to boiled or baked, eating the skin, and occasionally letting cooked potatoes cool before eating them.