Popeye Ate His Spinach
Especially when he needed strength and endurance. Why spinach? Check out the 1936 Popeye meets Sinbad the Sailor. Turns out that recent studies show that the mineral potassium (>200 mg per cup of spinach) is key to muscle strength and endurance, not to mention heart function, blood pressure, muscle cramps, energy, and more. Popeye was right!
I follow a number of low-carb and ketogenic diet related blogs and groups. Some are good, some are bad, some are doctors and researchers, some are not. You have to go to the science based groups that present their ideas based on good studies and data. On thing that has come up lately, is the subject of Potassium (K) deficiency. There are new studies showing the functions of potassium in the body, the symptoms of K deficiency and the benefits of supplementing potassium. Your body needs 4700 to 6000 mg/day from all sources(2). What does Potassium do and why do we need it?
Potassium is one of the three important mineral electrolytes in the body: Sodium, magnesium, and potassium. These three are required for nearly all body functions.
And now for the technical details. Potassium is involved in two primary energy transport functions: The sodium-potassium (Na-K) pump and the H-K ATPase (creates stomach acid). Without getting into the details, the Na-K pump which move energy into cells. Calcium transport into cells is dependent on potassium, without calcium, muscles can’t relax. It is estimated that a third of food energy goes to running the millions of tiny cellular NA-K energy pumps. Hence potassium is essential.
Symptoms of deficiency.
Low potassium levels cause a wide range of symptoms. Potassium is key to energy movement in the body, so it is no surprise that it can cause:
- Muscle Weakness
- Muscle cramps
- Sugar craving
- High Blood pressure
- Abnormal heart beat
- Rise in insulin levels
Dr. Eric Berg as a nice video on potassium deficiency and its causes.(2) In it, he lists the causes of potassium deficiency:
- Vomiting and/or diarrhea expel electrolytes
- Diets very low in potassium (i.e. no leafy greans)
- Ketosis – diuretic due to fat loss
- Diuretics – loose electrolytes with water
- Diabetes (high insulin levels)
- High cortisol
- Excess water – drinking too much causes kidneys to dump water and electrolytes along with it.
- Excess salt – too much salt will not maintain the proper electrolyte balance between Na, K and Mg
Foods high in potassium.
Our ancestors ate foods that contained much more potassium than today’s highly processed industrial foods. Even the meats came from animals that were eating foods higher in potassium. Industrial farming strips the minerals from the soil, so modern vegetables have less potassium that our ancestors ate.(1)
So how to get enough potassium? High potassium foods include beans, dark leafy greens, potatoes, squash, yogurt, fish, avocados, mushrooms, and bananas. If you are on a ketogenic diet, then do dark leafy greens (such as spinach, kale, romaine, collards), yogurt, fish, avocados, mushrooms that are also low in carbohydrates.
The current recommended daily value for potassium is 3,500 milligrams (mg) but others believe that 4700-6000 mg is used by the body every day. Raising the potassium to sodium ratio has been found to help reduce kidney and heart disease as reported in this article. Supplements are available, recommended to use Potassium Citrate or Potassium Bicarbonate as they reduce the acidity in the kidneys. It was once thought that high potassium in the diet would cause kidney problems, but they now see that healthy kidneys are very capable of removing large amounts of potassium from the bloodstream.
Getting enough potassium will improve muscle performance and overall energy levels. Look at the symptoms of deficiency and that reads like modern life, supplementing improves all of those things. We all should be ensuring that we get enough through food and supplements.
You don’t have to eat your spinach straight out of the can like Popeye.
- Eur J Nutr 40 : 200–213 (2001) “Diet, evolution and aging The pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet” L. Frassetto R. C. Morris, Jr. D. E. Sellmeyer K. Todd A. Sebastian
- Dr. Eric Berg. “POTASSIUM: The MOST Important Electrolyte,” video. Dr. Berg has several videos on the subject worth watching.
- Science Daily, “Raising dietary potassium to sodium ratio helps reduce heart, kidney disease” Feb. 21, 2017. article link.