WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Potassium, a mineral and electrolyte, is essential for your cells, tissues, and organs to function properly. It plays a vital role in heart health, digestive, and muscular function, bone health, and more.
While potassium is found in many foods commonly consumed in the US – including fruits, vegetables, dairy products, salmon, sardines, and nuts – only 2 percent of US adults get the recommended daily amount of 4,700 milligrams (mg).1
This is especially problematic because potassium is a nutrient that needs to be kept in proper balance with sodium in your blood. If you consume too much sodium, which is common if you eat a lot of processed foods, you'll have an increased need for potassium.
Others who are at particular risk of low potassium, or hypokalemia, are those with chronic malabsorption syndromes, such as Crohn's disease, or those taking heart medicine (particularly loop diuretics).2
However, anyone who eats a poor diet – an excess of processed foods and not enough fresh, whole foods – is potentially at risk of inadequate potassium levels.
Optimizing Your Potassium Level Helps Lower Your Blood Pressure
The number of deaths due to hypertension, or high blood pressure, increased nearly 62 percent from 2000 to 2013, according to a new report from the US Centers for Disease Control and Prevention (CDC).3 Currently, about 70 million US adults struggle with the condition, which amounts to one in every three adults.
Only 52 percent of those who have been diagnosed have their blood pressure levels under control, and another one in three US adults has pre-hypertension, which means blood pressure is elevated and at risk of progressing to full-blown hypertension.4
Yet, many are not aware that an imbalanced sodium-potassium ratio may lead to hypertension, as a higher level of potassium may blunt the effect of excess salt on blood pressure.5
A recent meta-analysis revealed that daily potassium supplementation is associated with a reduction of blood pressure in patients with high blood pressure. The researchers noted:6
"The reduction in blood pressure significantly correlates with decreased daily urinary sodium-to-potassium ratio and increased urinary potassium. Patients with elevated blood pressure may benefit from increased potassium intake along with controlled or decreased sodium intake."
Similarly, one four-year observational study (the Prospective Urban Rural Epidemiology [PURE] study), which included more than 100,000 people in 17 countries, found that while higher sodium levels correlate with an increased risk for high blood pressure, potassium helps offset sodium's adverse effects.7
In the study, those with the lowest risk for heart problems or death from any cause were consuming three to six grams of sodium a day — far more than US daily recommended limits. So while there is a relationship between sodium and blood pressure, it's not a linear relationship, and potassium plays a role.
Increasing Potassium May Be More Important Than Decreasing Salt for High Blood Pressure
The authors proposed that instead of recommending aggressive sodium reduction across the board, it might be wiser to recommend high-quality diets rich in potassium instead.
This, they surmised, might achieve greater public health benefits, including blood-pressure reduction. As noted by one of the researchers, Dr. Martin O'Donnell of McMaster University:8
"Potatoes, bananas, avocados, leafy greens, nuts, apricots, salmon, and mushrooms are high in potassium, and it's easier for people to add things to their diet than to take away something like salt."
For comparison, according to a 1985 article in The New England Journal of Medicine, titled "Paleolithic Nutrition," our ancient ancestors got about 11,000 mg of potassium a day and about 700 mg of sodium.9 This equates to nearly 16 times more potassium than sodium.
In contrast, daily potassium consumption with the Standard American Diet averages about 2,500 mg, along with 3,600 mg of sodium.
Researchers have also determined that increasing average potassium intake to the recommended 4,700 mg a day would reduce systolic blood pressure by between 1.7 and 3.2 mm Hg on a population-wide scale.
This decrease, they suggest, is similar to the reduction that would occur if Americans lowered their salt intake by 4 grams a day.10 This isn't to say that I advise consuming all the salt you want, of course, particularly if it's processed salt.
The easiest way to achieve an imbalance in your sodium-to-potassium ratio is by consuming a diet of processed foods, which are notoriously low in potassium while high in processed salt.
Potassium May Lower Your Risk of Stroke
Consuming enough potassium isn't only a matter of maintaining a healthy blood pressure; it also helps to lower your risk of stroke (which makes sense, since elevated blood pressure is a major risk factor for stroke).
Research found that women without hypertension who consumed the most potassium (nearly 3,200 mg/day) had a 21 percent reduced risk of stroke.
Further, women who consumed the most potassium were 12 percent less likely to suffer from a stroke, and 12 percent less likely to die during the study period, than those who consumed the least.11 According to the study's lead researcher:12
"Potassium may play a role in improving blood vessel function in our brains. This could allow better oxygenation of our brain tissue, and prevent tissue death that occurs from lack of oxygen to the brain… The effect of potassium consumption on reduced stroke risk could also be due to a better diet overall, though we did not investigate this in our study."
Separate research also revealed that for every 1000-mg/day increase in potassium intake, the risk of stroke decreased by 11 percent. "Dietary potassium intake is inversely associated with risk of strok.,"
The researchers wrote, "in particular ischemic stroke."13 (Ischemic stroke, the most common type, results from an obstruction in a blood vessel supplying blood to your brain.)
Why You Should Strive to Get Your Potassium from Your Diet
It's typically preferable to get your nutrients from foods instead of supplements, and this is certainly the case with potassium. Potassium in fruits and vegetables is potassium citrate or potassium malate, while that found in supplements is typically potassium chloride.
The citrate, malate, and other compounds in dietary potassium, particularly that in produce, helps your body produce alkali, which may promote bone health14 and even help preserve lean muscle mass as you get older.15 As researcher Dr. Bess Dawson-Hughes, of Tufts University, explained to Nutrition Action:16
"If you don't have adequate alkali to balance the acid load from the grains and protein in a typical American diet, you lose calcium in the urine and you have bone loss…
When the body has more acid than it is easily able to excrete, bone cells get a signal that the body needs to neutralize the acid with alkali… And bone is a big alkali reservoir, so the body breaks down some bone to add alkali to the system."
That bone loss could lead to brittle bones or even osteoporosis over time. But while potassium in fruits and vegetables may help build bone health, the potassium chloride in supplements may not.
Research by Dawson-Hughes found that people who were in the neutral range for net acid excretion, meaning they had a fairly healthy balance for bone and muscle health, were eating just over eight servings of fruits and vegetables a day along with 5.5 servings of grains.
When they rounded this out, it came to about half as many grains as fruits and vegetables. For many Americans a simple recommendation to increase your alkali (and potassium) while reducing acid is to eat more vegetables and fewer grains.17
What Else Is Potassium Good For?
There's no doubt that potassium is a superstar for heart health, lowering both your risk of high blood pressure and stroke. It's also beneficial for lowering your risk of heart disease. According to the University of Maryland Medical Center:18
"Studies show that [people with] a higher sodium-potassium ratio have a higher risk of heart disease and all-cause mortality. Other studies show that heart attack patients who have moderate potassium levels… have a lower risk of death."
As mentioned, eating a diet rich in potassium is also associated with bone health, particularly in elderly women, and, possibly, reducing the risk of osteoporosis. Symptoms of low potassium include weakness, lack of energy, muscle cramps, stomach disturbances, an irregular heartbeat, and an abnormal EKG (electrocardiogram, a test that measures heart function).19 If you're wondering what your potassium levels are, ask your physician for a blood test.
Is Your Sodium-to-Potassium Ratio Out of Balance?
If you eat a lot of processed foods and not many vegetables, there's a good chance your sodium-to-potassium ratio is unbalanced. If you're not sure, try a free app like My Fitness Pal, which allows you to enter the foods you eat and then calculates the ratio automatically. It's generally recommended that you consume five times more potassium than sodium, but most Americans get two times more sodium than potassium. If your ratio is out of balance…
- First, ditch all processed foods, which are very high in processed salt and low in potassium and other essential nutrients
- Eat a diet of whole, unprocessed foods, ideally organically and locally grown to ensure optimal nutrient content. This type of diet will naturally provide much larger amounts of potassium in relation to sodium
- When using added salt, use a natural salt. I believe Himalayan salt may be the most ideal, as it contains lower sodium and higher potassium levels compared to other salts
I do not recommend taking potassium supplements to correct a sodium-potassium imbalance. Instead, it is best to simply alter your diet and incorporate more potassium-rich whole foods. Green vegetable juicing is an excellent way to ensure you're getting enough nutrients for optimal health, including about 300 to 400 mg of potassium per cup. Some additional rich sources of potassium are:
- Lima beans (955 mg/cup)
- Winter squash (896 mg/cup)
- Cooked spinach (839 mg/cup)
- Avocado (500 mg per medium)
Other potassium-rich fruits and vegetables include:
- Fruits: papayas, prunes, cantaloupe, and bananas. (But be careful of bananas as they are high in sugar and have half the potassium of an equivalent amount of green vegetables. It is a myth that you are getting loads of potassium from bananas; the potassium is twice as high in green vegetables)
- Vegetables: broccoli, Brussels sprouts, avocados, asparagus, pumpkin, Swiss chard, and beet greens