Are Potatoes Acidic or Alkaline?
Clearly alkaline: boiled potatoes have a PRAL of −6.5 per 100 g and sweet potatoes −5.3, which makes potatoes the most alkaline starchy side dish there is.
Why potatoes are alkaline
Potatoes are rich in potassium and low in phosphorus and protein. That is exactly the combination that produces a negative PRAL. A 200 g serving adds −13.1 to your daily balance, which offsets a 100 g piece of meat almost exactly. By comparison, pasta comes in at +5.8 and rice at +1.8 per 100 g.
The same goes for mashed potatoes (−3.7) and potato gratin (−4.0). Even french fries (−11.4) and potato chips (−17.0) have negative values, because frying concentrates the potassium. That doesn't make them healthy. It only shows that PRAL measures a single thing: the acid load, not fat, salt or calories.
Acidic or alkaline: PRAL, not pH
The PRAL (potential renal acid load) estimates what a food leaves behind after digestion. It is not the pH of the food itself: a lemon tastes sour, yet its PRAL is −4.0. If you are asking whether potatoes are acidic because of heartburn or reflux, that is a question of pH and your stomach, which the PRAL does not measure; talk to your doctor about it.
Potatoes in different forms: raw, cooked, processed
How the PRAL changes with state and product. All values per 100 g or 100 ml.
| Food | PRAL |
|---|---|
| Potato (boiled) | −6.5 |
| Sweet potato (boiled) | −5.3 |
| Mashed potatoes (prepared) | −3.7 |
| Potato gratin (prepared) | −4.0 |
| French fries, fast-food (fried) | −11.4 |
| Potato chips naturale (fried) | −17.0 |
Goes well with
Frequently Asked Questions
Are sweet potatoes more alkaline than regular potatoes?
No, slightly less. Boiled sweet potato comes in at −5.3 per 100 g, boiled potato at −6.5. Both are very good alkaline side dishes.
Are french fries acidic or alkaline?
By PRAL, they are alkaline (−11.4), because the potassium is retained. That says nothing about their fat and salt. French fries are an exception, not a strategy.
Should you eat potatoes with or without the skin?
With the skin, you get more minerals and fiber. For the PRAL, the difference is small. For nutrient density, it isn't.
Potatoes and everything else on your plate: calculated automatically.
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More vegetables & salad compared
All vegetables & salad with their PRAL: Vegetables & Salad table. Back to the overview Acidic or Alkaline?, or put together a meal in the PRAL calculator.
Source: Basentracker food database (PRAL according to Remer & Manz, calculated from protein, phosphorus, potassium, magnesium and calcium per 100 g). This information does not replace medical advice.