To stay healthy and make sure our bodies are strong and energised, we need to get plenty of nutrients from our diet. There are many essential vitamins that our bodies rely on, but minerals are just as important.
Potassium is considered an essential mineral. But what exactly does it do? Why is it so important, and how can we make sure that we’re getting enough?
Here’s everything you need to know about potassium…
What is potassium?
Potassium is an essential mineral that’s found in food and it’s the third most abundant mineral in the body.
Potassium is needed for several key processes, including proper heart, kidney, and muscle function – and for making sure that cells contain normal levels of fluid.
Because it carries a small electrical charge and conducts energy when dissolved in water, potassium is an electrolyte. By sending electrical impulses through the body, potassium plays a key role in regulating blood pressure, digestion, and heart rhythm.
Our bodies don’t produce potassium naturally, so to stay healthy we need to eat enough potassium-rich foods.
Why is potassium important?
Potassium is needed for the normal functioning of our cells, and it has many key roles within the body. 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 weaken.
You also need to have healthy levels of potassium for your heart to beat properly. Potassium levels that are too low or high can impair heart contractions, which can cause an irregular heartbeat or arrhythmia – both of which can be dangerous.
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 the 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 shrink as water exits them, or swell and burst as water enters.
When your fluids aren’t balanced, you risk becoming dehydrated, which can harm your heart and kidneys. Because electrolytes are so important for fluid balance – and because we lose them through sweat – they’re a key component of sports drinks.
Potassium may help reduce blood pressure
In the UK, a third of adults suffer from high blood pressure, and this can increase the chance of developing heart disease.
High levels of sodium can elevate blood pressure, but because potassium helps the body remove excess sodium, it’s believed it can also help reduce blood pressure.
This meta-analysis found that when people with high blood pressure consumed more potassium, their blood pressure dropped. A study of 1,285 participants also found that those who consumed the most potassium had lower blood pressure, compared to the people who ate the least.
For further advice, you might find our article, 10 natural ways to lower blood pressure, useful.
Potassium may protect against stroke
Strokes occur when there isn’t enough blood flow to the brain.
Research shows that eating a potassium-rich diet can help to prevent strokes. For example, this review found that people who ate more potassium had a 24% 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, because potassium can reduce the amount of calcium the body loses through urine. This may help to prevent osteoporosis.
This study of women aged 45 to 55 showed that those who consumed the most potassium had the greatest bone mass. Other studies of premenopausal women have also revealed that women who consume more potassium have a higher bone mineral density.
Potassium may protect against kidney stones
Potassium is also believed to help prevent kidney stones. These occur when clumps of minerals (like calcium) form in the kidneys. Research shows that healthy potassium levels can help to lower calcium levels in urine, which lowers the risk of kidney stones.
For example, this study of over 45,000 men found that those who consumed the most potassium had a 51% lower risk of kidney stones. While another study of almost 92,000 women showed that those who consumed the most potassium had a 35% lower risk of kidney stones.
How to make sure you’re getting enough potassium
Potassium plays a crucial role in the body, but 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 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 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, the NHS suggests that older adults don’t take potassium supplements unless advised to by their doctor.
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 losing up to 800mg a day is normal. However, if you’ve been experiencing vomiting, diarrhoea, excess sweating, or you’ve been taking diuretic medication, you’re at greater risk of losing 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
Potassium is abundant in many plant-based foods, especially fruits, vegetables, and pulses, while processed foods contain lower potassium levels.
While bananas are probably the most well-known potassium-rich food source, there are lots of delicious foods that contain high amounts of potassium. Below, you’ll 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%)
Potassium-rich fruits and vegetables 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
- Whole wheat bread, rice and pasta
For potassium-rich recipe ideas, why not check out this list from Eating Well?
Final thoughts…
When it comes to staying healthy, potassium plays an essential role. It helps regulate fluid levels in our bodies, improves muscle function, keeps our nervous system working properly, and plays a key role in heart health.
Potassium is present in many different foods – especially in healthy whole foods like fruits, vegetables, and pulses. So, adding more potassium-rich foods to your diet will likely benefit your overall health too.
Most of us get enough potassium from eating a balanced diet, and for this reason supplements aren’t usually recommended unless you’re at risk of potassium deficiency. If you’re worried about your potassium levels, you should always speak to your GP before taking 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? We’d be interested to hear from you in the comments below.
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