Does cooking potatoes lower potassium?

Every time I google something like this I just get an infinite string of articles on how to LOWER potassium in potatoes.
The RDA for potassium is practically unreachable. It’s like 8 bananas or something or 7 potatoes you have to eat to get it. Now I know raw potatoes are excellent and cooking generally lowers nutrients, but is potassium one of the things that gets significantly lowered when cooking them?

The Nutrition Data site has roughly the same values for cooked and raw potatoes.

Unless something changed recently there is no RDA for potassium and only the minimum required intake is known. Plenty of foods do contain potassium though, you shouldn’t need to concentrate on the high potassium foods. Milk has a lot of potassium as well as whole grains, meat, and green vegetables.

Potassium is an element and cannot be destroyed or changed by cooking.

If you boil the potatoes, I suppose some potassium might be leached off. But then it would be in the water, which you could drink.

Baking the potatoes should not result in any decrease in potassium level.

Potassium isn’t present in foods in elemental form though. It may be more or less bio-available depending on its place in different molecules, and those molecules could be changed by heat. IANAB but perhaps others with more knowledge of human biology can weight in.

If you’re using a nutrient-tracking app like MyFitnessPal or Fitday, you should be aware that their potassium data isn’t very reliable. A lot of packaged foods, ready-to-eat foods, and user-entered foods in their databases are listed as having no potassium, even those that in fact contain quite a bit. In part, that’s because potassium is rarely listed on nutrition labels. If you want a better idea of how much potassium you’re getting, try using the USDA nutrient database.

Potassium is present as an element, in the form of K+ ions in solution. Even if the potassium was present as an undissolved ionic compound, it would be totally unaffected by the heat of cooking.

Thanks, I should have remembered that from high school biology.

And should it not then mostly end up in the water when potatoes are boiled?

Yeah I always mention to people “trying to get enough potassium”, that meat has a ton of it and that’s not widely realized because unlike sodium or fat, potassium isn’t yet a mandatory line on the nutrition facts label. For example a 3.5oz serving of cooked chicken breast contains about 300mg of potassium.

Dried fruit also has off the charts potassium. 25g of dried apricots have 1800mg of potassium.

Some of it will. The rest will stay inside the cells or attracted to other charged compounds.

I would expect boiling to break down many of the cells, although this no doubt varies by how long the boiling lasts.

But the “attracted to other charged compounds” bit doesn’t wash, so to speak. Sodium and chlorine are attracted to each other in salt, yet when dissolved, they’re separated by water molecules.

Rinsing potatoes will reduce the amount of potassium in them. I have a friend that is on dialysis, and potassium content of food is always an issue for him, in that he has to keep his intake low. Rinsing raw sliced/diced/shredded potatoes multiple times, or cooking them multiple times in water with a water change each time, reduces the potassium contents enough that he can eat them.

How is it that there are articles with “how to lower the potassium level in your potatoes by cooking them” as an advice factoid?

Who isn’t already cooking potatoes before eating them? I have only met one person in my lifetime that ate raw potatoes, and she acknowledged herself that she thought it was weird.

Most people cook potatoes, but there are many different ways to cook them. Only boiling will remove potassium, and even then it’ll depend on how much water they’re boiled in and how thin they’re sliced.

Not true as a blanket statement. Cooking makes many nutrients more available to our digestive system, which is why we do it. Some nutrients are reduced if you cook in water, especially water-soluble vitamins.

It’s not even as simple as “cooked in water”, either. Sure, if you boil potatoes, then a lot of the nutrients end up in the water… but at least the way my family does it, it’s also true that most of the water ends up in the potatoes. When you start them, there’s just enough water to cover the potatoes, and by the time you finish, there’s almost no water left in the pan at all.

Now, if you’re specifically trying to reduce those nutrients, because you need a low-potassium diet or whatever, then you can use a bigger pot and add a lot more water. But that’s not the way most folks do it.