Potassium Health Benefits and Use

In this Article (Index)

• Potassium
• Recommended Daily Allowance for Potassium
• Dietary Sources of Potassium
• The Benefits of Potassium in Your Diet
• Lower Blood Pressure
• Bone Health
• Kidney Disease
• Side Effects

Potassium

Potassium is an essential nutrient that is vital in maintaining the cells' fluid and electrolyte balance. It is found in all animal and plant tissues.

It is a soft silvery metallic element with 19 protons; its chemical symbol is K, derived from its Latin name "kalium." Potassium gets its name from potash, as it was originally obtained by leaching the ashes of plants and wood and then evaporating the solution in iron pots, hence "pot" + "ash."

Roughly 90% to 95%) of potassium in the human body is stored inside the muscle and bone cells. (1)

Potassium is alkaline like sodium, and when dissolved in water it forms a positive ion called a cation, K⁺. Sodium behaves similarly, forming the Na⁺ cation. Both elements are linked in the body's biochemistry.

While sodium is the major cation outside the body's cells, potassium is the major cation inside them. For instance, in neurons, the concentration of potassium cations is roughly 30-fold larger inside than the outside, whereas the sodium concentration outside is around five times larger outside than inside.

This difference in concentration creates a difference in the electric potential across cell membranes which has important physiological effects.

The kidneys regulate potassium balance and dispose of most of the potassium we ingest through urine.

Function: Health effects

There is an association between potassium and blood pressure: a higher intake of potassium in combination with a low-sodium diet lowers blood pressure. Studies have also suggested that dietary potassium can lower the risk of stroke, coronary heart disease, and kidney diseases like chronic kidney failure and kidney stones.

Dietary Sources

We obtain our potassium from the food we ingest, potassium is found in many different types of foods like vegetables, fruit, dairy products, meat, fish, and seafood.

Recommended Daily Allowance for Potassium

The World Health Organization (WHO) recommends a daily potassium intake of at least 3,510 mg/day for adults, and the United States Department of Agriculture (USDA) has set the Adequate Intake (AI) for potassium for adults at 4,700 mg/day. (1)

The USDA has recognized this deficiency in potassium and identified it as a nutrient of public health concern.
The average potassium intake of Americans is nearly half of the just over half of the required intake (2,590 mg/day.) (2)

This shortfall in potassium intake is due to the "Western diet" composed mainly of processed foods with a high sodium and low potassium content, and a reduced intake of fruits and vegetables (which are potassium-rich foods).

Because of the American diet, the main potassium sources for adult Americans are milk, coffee, chicken and beef, orange and grapefruit juice, and potatoes. ((2)
In the following section, we will check out potassium-rich foods that should form part of A Balanced Diet.

Dietary Sources of Potassium

Below are some food sources listed by the amount of potassium they contain in a regular food portion. (2),(5)

Check the USDA's full list of potassium-rich foods.

Fruits and vegetables have a high potassium content with the advantage of lower calories and the plant-based phytochemicals and fiber that come with them.

The Benefits of Potassium in Your Diet

• Lower Blood Pressure
• Bone Health
• Kidney Disease

Lower Blood Pressure

There is evidence linking potassium intake to blood pressure reduction, this helps lower the risk of heart disease.

Studies have shown that the intake of starchy vegetables like potatoes is associated with a lower risk of stroke, however, salt intake should be limited. (2)

The best combination seems to be a high-potassium / low-sodium diet, because both nutrients combined have a larger effect than each one, individually.
The highest benefits have been observed in salt-sensitive individuals and those consuming large amounts of salt.

A meta-analysis involving approximately 250,000 individuals found a stroke risk reduction of 21% for every 1,640 mg/day increase in potassium intake. (2). Considering that Americans should be consuming 4,700 mg/day, but on average have an intake of 2,590 mg/day, just increasing intake to the recommended levels could reduce the risk of stroke by 27%.

Salt restriction lowers blood pressure quite fast, however, potassium supplementation takes about 4 weeks to act. (6).

How does potassium lower Blood Pressure?

One mechanism is that it promotes the urinary excretion of sodium, lowering its concentration. (6). Furthermore, sodium in the presence of aldosterone tends to stiffen the cells that line the blood vessels, reducing the release of nitric oxide. But, potassium swells and softens these endothelial cells increasing the release of nitric oxide which acts as a vasodilator, meaning that it relaxes and widens blood vessels. Improving blood flow and lowering blood pressure. (4)

Bone Health

A higher intake of dietary potassium has a positive impact on bone health vs. supplements.

Dietary Potassium is Better than Supplements

The natural sources of potassium (fruits, and vegetables) provide different types of potassium salts compared to the potassium chloride supplements. Supplements and dietary sources are equally effective for hypertension, but natural potassium provides bone health benefits that supplements don't.

These benefits are seen when organic salts are ingested in doses of 2,400 to 3,600 mg/day. They could also occur at lower levels but further trials are needed to confirm this.

It is also likely that the flavonoids found in fruits and vegetables also help improve bone health. Flavonoids are polyphenols that help reduce age-related bone loss. So, it is difficult to establish if the potassium or the flavonoids found in plants and vegetables provide bone health benefits. (2).

Nevertheless, potassium intake reduces the urinary excretion of calcium neutralizing the Net renal acid excretion or NRAE, and this improves the body's calcium balance.

Kidney Disease

There is evidence that suggests that dietary potassium can help reduce kidney stones. Studies conducted on hypertensive rats showed that a high intake of potassium prevented kidney damage on the vascular, tubular, and glomerular levels. However, studies in humans are necessary to corroborate these findings. (2)

Side Effects

Potassium supplements can cause gastrointestinal side effects like diarrhea, nausea, vomiting, and abdominal pain.

Hyperalkemia (excess potassium in the body) is another serious adverse reaction. It happens when the kidneys can't eliminate potassium fast enough, and it accumulates in the body; it can cause neuromuscular effects like temporary paralysis. This can affect people with renal failure. It can lead to an abnormal heart rhythm (arrhythmia) and cause a heart attack.

Talk to your doctor before starting any new over-the-counter medication or supplement, including Potassium supplements.