7 things you need to know about potassium

Commonly associated with bananas, this key nutrient shouldn’t be underestimated.

We get the lowdown on potassium.

Potassium is a key nutrient for day-to-day body function

Potassium, also known as an electrolyte, helps regulate fluid, send nerve signals, and muscle contraction.

Poor fluid regulation can lead to dehydration, which in turn can have an adverse impact on heart and kidney function.

Inadequate potassium levels in your blood can negatively affect how your body generates nerve impulses and weaken muscle contraction.

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Potassium lowers your risk of serious health issues

Getting the right amount of potassium also lowers the risk of stroke, maintains muscle mass and bone density, and makes it less likely that you will get painful kidney stones.

US researchers are also looking at how potassium may help protect against heart disease by reducing hardening and narrowing of the arteries that lead to stroke and heart attack.

Potassium is important for maintaining healthy blood pressure

While it’s well known that having less salt in our daily diet helps lower high blood pressure, potassium also has a role to play.

“Reducing salt is important but improving potassium intake can also help improve blood pressure control, because sodium and potassium work together,” explains dietitian Aloysa Hourigan, of Nutrition Australia.

You’ll generally get enough potassium from a balanced diet

“If you eat a balanced diet, you will normally have enough potassium because it is found in many different foods, but fruits and vegetables are the main source,” says Aloysa.

“As a general rule, more yellow-coloured fruits and vegetables are higher in potassium.

“So, bananas, mango, pineapple, nectarines, pumpkin and corn are good sources.”

Avocado, legumes, kale and spinach, tomatoes, carrots and sweet potatoes are also rich in potassium.

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Men need about 3800mg of potassium a day, women need 2800mg

That’s according to National Health and Medical Research Council guidelines.

As a guide, a 100g serve of sweet potato has around 475mg of potassium while the same amount of avocado has around 485mg and 100 grams of banana has around 358mg.

Low potassium can be caused by medications, excessive sweating, vomiting or diarrhoea

Symptoms of low potassium include feeling extremely weak and tired, muscle cramps and constipation.

Very low potassium can also lead to abnormal heart rhythm.

A blood test can check your potassium levels and your GP will advise if you need a potassium supplement.

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Too much potassium can be potentially fatal

Possible signs of too much potassium are feeling weak and tired, nausea and an abnormal heart rhythm.

This can be a potential risk for people on some medications or with poor kidney function whose kidneys are not able to help balance potassium in the body and so levels build in the blood, says Aloysa.

“If you have kidney problems or high blood pressure then your GP will do regular blood tests to check that your sodium and potassium levels are in order,” she says.

Written by Sarah Marinos