As I understand it, there's "two oceans of water": one inside-the-cell and one outside-the-cell.
Sodium attracts water out of the cell and potassium attracts water inside-the-cell.
From what I understand, edema is when water accumulates outside-of-the-cell.
If that's the case, it would seem like increasing potassium, and decreasing sodium would be the objective.
I also read that for the potassium/sodium pump to function properly, sufficient magnesium is required.
Are there other co-factors that would help get water inside-the-cells instead of outside-the-cells?
[EDITED to add the following background]:
The reason I ask is it seems I'm having a terrible time balancing my electrolytes. Symptoms: muscle cramps, tension headaches, and occasional edema in feet (sometimes hands). Through a food diary, I have a set of suspect foods (kale, sweet potato, chocolate, which are high in oxalates) but I'm second guessing that conclusion because it might be the salt I'm having with those foods. I'm still experimenting. When things get really bad, my feet/hands cramp and swell, and I get muscle twitching.
I have 16oz of raw milk each day (so that should be enough calcium). I've read that raw milk offers the very most absorbable form of calcium around.
My BUN:creatinine ratio is 20 (normal is 10-20, with over 20 being an indicator of dehydration.). I drink more than 100 ounces of water/day (I'm 190lb male). My chiropractor administered a bio-impedance test (electrode on hand and foot) which reports the % of water inside-the-cells and outside-the-cells. The inside-the-cells was a bit lower than the reference range, but not hugely).
I've been working hard to ensure I'm getting enough magnesium (taking 500mg elemental magnesium in 4 jigsaw magnesium tabs/day. I just upped that to 6/day. I also have been using transdermal magnesium oil. The reason I'm currently focusing in on magnesium is that I have crohn's disease of the terminal ileum. Though I've been in remission for 20 years, there's lots of damage and scarring in that area of the intestine. That happens to be exactly where magnesium and B12 are absorbed so it seemed like a good hypothesis. (That's why I'm trying to also absorb magnesium through the skin, to bypass the intestine all together.).
My regular doc ran blood and urine tests and said everything is fine, which it clearly isn't.
I'm not sure if your question is about edema, so if you're trying to cure edema or if you're just trying to stay hydrated? But in general, I have read that salt is also important for hydration, so likely Chloride as well,
I'm not sure it would be as simple to cure edema by decreasing sodium/potassium ratios if that's what you're saying?
There are likely other factors as well as water contents of certain foods which would play a role. It's also not clear to me if certain micronutrients wouldn't influence this action, for example I know chromium is responsible for getting glucose into cells, but it's not clear if that should happen inside or outside of the cell (perfect health diet book, and I apologize if I've not said this correctly)
Edited to reflect the background update:
I know this might sound crazy but I had elevated BUN/Creatinine values eating the 1 g of protein/lean body mass (I think I was doing failed paleo diet).
I might actually recommend drinking less water and trying to get your "water" intake through food - tomatoes, lettuce, potatoes, or whatever foods high in potassium you can possibly eat. I think some water intake is normal, but I'm not sure if 100 ounces is necessary and if you're forcing yourself to drink it or just quite thirsty.
I also wonder if there isn't some other nutritional deficiency at work here, due to your medical background. Have you emailed Paul Jaminet or posted on their page?
Barring everything- here is an old post about edema:
How to take supplemental potassium ? 8 Answers