You may not realise it but right now – just as you’re researching another recipe or daydreaming about what to eat – your kidneys are hard at work in your body. They’re busy filtering waste, balancing your acid levels, making vitamin D and excreting toxins.
“Your kidneys are the best little powerhouses in your body,” says Dr Kelly Lambert, Clinical Advisory Committee member at Kidney Health Australia.
Yet, the work our kidneys do is underrated – often until it’s too late. Every year, 1.7 million Australians or 10 per cent of the population are affected by kidney disease.
“Kidney disease is irreversible and silent. So most people don’t know they have kidney damage until it's way too late.”
Your kidneys are the best little powerhouses in your body.
Some groups in society are more at risk of chronic kidney disease than others. If you smoke, live with type 2 diabetes, are overweight or obese or have high blood pressure, your chances of developing the deadly disease are increased.
According to Kidney Health Australia, Aboriginal and Torres Strait Islander peoples are also five times more likely to develop kidney disease, and four times more likely to die from kidney disease when compared to the general population.
Dr Lambert says if you don’t have kidney disease, there’s still time to prevent a diagnosis by changing the way you eat. “What you choose to eat now can influence whether you go on to develop kidney disease in the future,” states Dr Lambert, who's also an Advanced Accredited Practising Dietitian and renal specialist.
But if you already have kidney disease, it’s essential you take dietary advice from a medical professional, as the nutritional recommendations for disease prevention are very different.
How to eat to prevent kidney disease
Protein
Maintaining a balanced diet with the right amount of protein is essential to keep our kidneys in check. To protect your kidneys, Dr Lambert advises people to avoid ketogenic diets that encourage large protein serves.
“When you eat large portion sizes of foods that contain protein, you are increasing the filtration work that the kidneys need to do. When filters work hard over time, that's a bad thing.
“So having an appropriate portion size is a good thing of meat, chicken and fish. We recommend eating around 125-150 grams of meat chicken or fish at the main meal.”
What you choose to eat now can influence whether you go on to develop kidney disease in the future.
Obesity and type 2 diabetes
Dr Lambert also explains that to prevent kidney disease, you need to follow a diet that manages your underlying risk factors.
"If you’re overweight or obese, you need to lose weight in a safe, slow and sustained manner," she says. "Even if you lose just five per cent of your body weight, there will be less pressure on your kidneys.”
Following a diet that helps to manage type 2 diabetes will help to reduce your risk of developing kidney disease. If in doubt, seek a dietitian for nutritional support and advice.
Manage hypertension
People who live with high blood pressure are advised to reduce their salt intake and consumption of discretionary foods to lower their risk of kidney damage.
A diet that includes daily serves of fruit, vegetables and dairy has been shown to be effective in lowering blood pressure. These nutritional features are the foundations of Dietary Approaches to Stop Hypertension (DASH).
“The DASH diet has been proven to have a direct effect on blood pressure and reduce your risk of kidney damage. It’s all to do with the potassium load. We want people to have more potassium in their diet and less salt.”
More specifically, foods that are high in potassium are kidney beans, banana, mango, berries, stone fruits, pineapple, tomato, potato, pumpkin, spinach, milk, yoghurt, high fibre breakfast cereals, nuts and seeds, and dried fruits.
Head of Chinese medicine at Endeavour College, Shuai Zheng, provides an additional, diverse list of foods that are believed to be good for kidney health according to traditional Chinese medicine.
“To improve kidney function, black coloured food is quite good for the kidneys,” Zheng tells SBS. Black sesame, black fungus, kidney beans and black beans. Another food that we believe is good for kidneys is goji berries.”
These five foods also happen to be high in potassium.
Zheng says traditional Chinese medicine also encourages people to focus on the bigger health picture, not just one organ, and follow a balanced diet full of fruits, vegetables and wholegrains.
“We are big on balance overall. We want people to eat a diet that benefits your whole body rather than just one organ.”
A word of potassium caution
Dr Lambert reminds people who already have existing kidney disease that additional potassium in their diet could cause harm.
“You won’t be able to excrete that extra potassium and potentially have a cardiac arrest,” says Dr Lambert. “So it’s important for people with advanced kidney disease and high blood pressure to choose appropriate fruits and vegetables for their health.
“Rather than eating a banana, they may have an apple. Or instead of a tomato, they could opt for cucumber, just so they don’t overload on potassium.”
If you have advanced kidney disease, always exercise caution and consult your GP, renal specialist or a qualified dietitian for specific dietary advice to suit you.
To find out more information about kidney disease, visit Kidney Health Australia online or call the Kidney Helpline on 1800 454 363.
