To stay healthy and make sure our bodies are strong and energised, we need to get plenty of nutrients. There are lots of essential vitamins that our bodies rely on, but minerals are just as important.

Potassium is considered to be an essential mineral. So, what exactly does it do? Why is it so important, and how can we make sure we’re getting enough?

Here’s everything you need to know about potassium.

What is potassium?

What is potassium

Potassium is an essential mineral that’s found in the foods we eat. It’s the third most abundant mineral in our bodies, and around 98% of the potassium in our body is found in our cells.

Our bodies need potassium for several vital processes. Though, it’s especially important for proper heart, kidney, and muscle function – and for ensuring our cells contain normal levels of fluid.

Because it carries a small electrical charge and conducts energy when it’s dissolved in water, potassium is also an electrolyte. By sending electrical impulses through the body, potassium plays a key role in many important bodily functions, from blood pressure to digestion and heart rhythm.

Our bodies don’t produce potassium naturally, so to stay healthy we need to make sure we consume enough potassium-rich foods.

Why is potassium so important?

Why is potassium so important

Potassium is vital for the normal functioning of all our cells, and it has many key functions within our bodies. Let’s take a closer look at some of the powerful health benefits of this wonder mineral…

Potassium regulates muscle contractions and heartbeat

Potassium plays a key role in transmitting messages through the nervous system, and two of the most important signals relate to our muscles and heart.

If you don’t have healthy levels of potassium in your blood, the nerve signals in your nervous system can be affected, and muscle contractions can become weakened.

You need to have healthy blood levels of potassium for your heart to beat properly. If potassium levels are too low or too high, heart contractions can become weakened, which can cause an irregular heartbeat or heart arrhythmia. This condition can sometimes lead to sudden death.

Potassium regulates fluid balance

The human body is made up of around 60% water, 40% of which is intracellular fluid (ICF), which lives inside our cells. The remaining water is called extracellular fluid (ECF), and this is found outside our cells – in blood, in between cells, and in spinal fluid.

The amount of water in both ICF and ECF is determined by their concentration of electrolytes, particularly potassium and sodium. To perform at its peak, your body needs to have an equal balance of these electrolytes. When it’s unequal, cells can either shrink as water exits them, or swell and burst as water enters them.

When your fluids aren’t balanced, you can become at risk of dehydration, which can harm both your heart and kidneys. Because electrolytes like potassium are so important for fluid balance – and because we lose them when we sweat – they’re a key component of sports drinks. This is why athletes tend to be more focused on potassium levels than the average person.

Potassium may help reduce blood pressure

In the UK a third of adults suffer from high blood pressure, and this common condition can significantly increase your chances of developing heart disease.

Having high levels of sodium can elevate blood pressure – but because potassium helps the body get rid of excess sodium, it’s believed it can also help reduce blood pressure.

A meta-analysis of 33 different studies found that when people with high blood pressure consumed more potassium, their blood pressure dropped. Another study of 1,285 participants found that the people who consumed the most potassium showed the most reduced blood pressure, compared to the people who ate the least.

Potassium may protect against stroke

Strokes occur when there isn’t enough blood flow to the brain. In the UK, stroke is the fourth single leading cause of death and a leading cause of disability.

Research shows that eating a diet that’s rich in potassium can help prevent strokes. A meta-analysis of 33 studies showed that people who ate the highest amounts of potassium had a 24% lower risk of stroke than people who ate the least.

Other studies show similar results; another meta-analysis of 11 studies (with almost 250,000 participants) found that the people who ate the most potassium had a 21% lower risk of stroke.

Potassium may help maintain bone strength

Potassium may also play a role in bone health. Research shows that people who eat a potassium-rich diet may have higher bone mineral density.

Osteoporosis is a condition that causes bones to become brittle and weak, and it’s often linked to having low levels of calcium. Studies show that potassium can reduce the amount of calcium the body loses through urine, which may in turn help prevent osteoporosis.

One study of women aged between 45–55 showed that the women who consumed the most potassium had the greatest bone mass. Other studies of premenopausal women showed that the women who consumed the most potassium had more bone mass in their back and hips.

Potassium may protect against kidney stones

Potassium is also believed to prevent kidney stones. Kidney stones occur when clumps of minerals like calcium form in the kidneys. Studies show that having healthy levels of potassium can help to lower calcium levels in urine, thus lowering the risk of kidney stones.

One four-year study of more than 45,000 men found that those who consumed the most potassium had a 51% lower risk of kidney stones. Another 12-year study of almost 92,000 women showed that the women who consumed the most potassium had a 35% lower risk of kidney stones.

How to make sure you’re getting enough potassium

How to make sure you're getting enough potassium

So, we know that potassium plays a crucial role in our bodies, and is especially important for sending nerve signals, regulating muscle contractions like heartbeat, and controlling the balance of fluids.

Potassium is also associated with many other powerful health benefits – and because the human body can’t produce potassium itself, we need to make sure we’re getting enough from our diet.

But how much potassium exactly do we actually need?

According to the NHS, adults under the age of 64 need 3,500mg of potassium a day – and we should be able to get that from eating a healthy, balanced diet.

However, consuming too much potassium can cause stomach pain, nausea, and diarrhoea. Having high levels of potassium in the blood is called hyperkalemia, and the NHS states that older adults are more at risk of this, because their kidneys may not be as effective at removing potassium from the blood.

For this reason, it’s advised that older adults and people who have issues with their kidneys shouldn’t take potassium supplements unless specifically advised to by their doctor. Although, taking less than 3,500mg of potassium supplements a day is unlikely to cause harm (NHS).

Because potassium is found in so many foods, deficiency is rare. Potassium is generally flushed out of our bodies through urine, sweat, and stools, and a loss of up to 800mg a day is normal. However, if you’ve been experiencing vomiting, diarrhoea, or excess sweating, or you’ve been taking diuretic medications, you’re at greater risk of losing too much potassium and becoming deficient.

Signs of potassium deficiency include fatigue, muscle cramps or weakness, constipation, and – if severe – muscle paralysis and irregular heart rate.

The best food sources of potassium

the best food sources of potassium

Potassium is abundant in many plant-based foods, especially fruits, vegetables, and pulses. Processed foods contain reduced levels of potassium, so if you eat a lot of processed foods, you’re more likely to have lower levels of potassium.

While bananas are probably the most known potassium-rich food source, there are lots of delicious foods that contain high amounts of potassium. Below you can find a list of potassium-rich foods, and how much of your daily potassium intake is contained in one serving.

  • Dried apricots – 1,101mg (23%)
  • Cooked lentils – 731mg (16%)
  • Dried prunes – 699mg (15%)
  • Squash – 644mg (14%)
  • Baked potato – 610mg (13%)
  • Kidney beans – 607mg (13%)
  • Orange juice – 496mg (11%)
  • Soya milk – 443mg (9%)
  • Banana – 422mg (9%)

But there are many fruits and vegetables that are also rich in potassium. These include:

  • Spinach (cooked)
  • Broccoli (cooked)
  • Sweet potatoes
  • Mushrooms
  • Peas
  • Cucumbers
  • Courgette
  • Leafy greens
  • Cantaloupe and honeydew melon
  • Grapefruit

Beans and legumes that are rich in potassium include:

  • Soya beans
  • Lentils
  • Lima beans
  • Pinto beans
  • Kidney beans

Other foods that contain potassium include:

  • Nuts
  • Some fish (tuna, halibut, cod and trout)
  • Bran cereal
  • Wholewheat bread, rice and pasta

To find out more about foods that are rich in potassium, check out this article by Everyday Health.

Final thoughts…

When it comes to staying healthy, potassium plays a crucial role. It helps regulate fluid levels in our bodies, improves muscle function, keeps our nervous system functioning properly, and plays a key role in heart health.

Potassium is present in many different types of foods we eat, but it’s especially prevalent in healthy wholefoods like fruits, vegetables, and pulses. Therefore, trying to add more potassium-rich foods to your diet will be beneficial to your overall health, as well as for the specific reasons cited in this article.

Because potassium is so abundant in many healthy foods, most of us can get enough from eating a balanced diet, and for this reason supplements are not usually recommended unless you’re at risk of a potassium deficiency. If you’re worried about your potassium levels, you should always speak to your GP before starting to take any supplements.

To find out more about the essential vitamins and minerals our bodies need, head over to the diet and nutrition section of our website.

Do you think you get enough potassium – or do you have any more tips for staying healthy? Join the healthy living conversation on the Rest Less community forum, or leave a comment below.


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