Best Foods For Your Kidney

The kidney has various roles within the body, the main one being regulating and maintaining the body’s internal environment by excreting waste products. Therefore, it is essential to keep the kidneys healthy to ensure that they can carry out their functions to the best of their ability. 

There are several ways in which you can take care of your kidney health, with the main one being good nutrition. Maintaining a balanced diet containing foods with low levels of sodium and phosphorous, high levels of potassium and antioxidants, and lots of protein can help maintain good kidney health. This article will highlight some of the most important dietary factors to consider for good kidney health and how to incorporate them into the diet.

Importance of kidney health

Kidneys are bean-shaped organs that play vital roles in our bodies. One of your kidneys is roughly the size of a closed fist and weighs between 150-200 grams and 120-135 grams in males and females, respectively. Some of the main functions of the kidney include the excretion of waste products, regulating electrolyte levels, and maintaining a balance between acids and bases.¹ 

Due to the variety of roles performed by the kidneys, it is essential to make healthy lifestyle choices to ensure that they remain in good condition or prevent them from getting worse, especially in people suffering from chronic kidney disease (CKD).² 

Chronic kidney disease refers to the presence of kidney damage or low filtration rate. CKD also results in the gradual loss of kidney function, leading to renal replacement therapy, dialysis, or kidney transplantation.³

Diet and kidney function 

Diet is one of the most crucial aspects of our general health, including kidney health. Healthy food choices can help protect our kidneys in a variety of ways, including providing a good source of energy, preventing infection, reducing muscle loss, contributing to healthy weight, and slowing down the progression of kidney diseases, including CKD. 

Good nutrition and incorporating the right amount of protein, sodium, potassium, phosphorous and calcium into your diet helps with regulating and controlling the levels of waste and fluid in the blood. A blood test can be conducted by a healthcare professional to identify the appropriate nutrients and amounts to incorporate into your diet.²

Best foods for the kidney

There are many nutrients and foods which need to be considered when thinking about kidney health, as they can help with kidney function and prevent the progression of kidney-related diseases including CKD.² Some of the foods recommended include foods with low levels of sodium and phosphorous, high levels of potassium and antioxidants, protein and healthy fats. 

Low-sodium foods

One of the roles of kidneys involves regulating the levels of sodium in the body. Worsened kidney health can result in a higher concentration of sodium in the body, causing swelling, high blood pressure, and cardiovascular problems. The World Health Organisation (WHO) has advised that adults should consume less than 2.3 grams of sodium a day (equivalent to 5.8 grams of salt). 

In addition to high sodium concentrations causing a negative effect on kidney health, it can also lead to increased blood pressure and in turn increase your risk of cardiovascular disease (CVD).⁴ Some examples of foods containing low levels of sodium include:

• Fresh fruits and vegetables 
• Canned vegetables or fruits that are low in sodium or have no salt added
• Whole grains like brown rice, quinoa and barley
• Eggs
• Fish, shellfish, and chicken/turkey breast without skin
• Fat-free or low-fat milk/yoghurt

Furthermore, it is advisable to prioritise fresh foods instead of processed foods, and check food labels with ‘low sodium’ or ‘no salt added’.⁵

High-potassium foods

The nutrient potassium has many roles in our body and health, including regulating the concentration (osmolality) of substances within our cells and maintaining fluid balance. The levels of potassium in our blood are regulated by the kidneys which excrete around 77% to 100% of ingested potassium in the urine within 24 hours of its consumption. 

A high intake of dietary potassium can lower your blood pressure and risk of both cardiovascular and kidney disease, including CKD and kidney stones. Therefore, it is essential to consume foods with high levels of potassium. Some of the foods containing high potassium levels include fruits, vegetables, rice, potatoes and whole grains.⁶

Low-phosphorus foods

The kidneys are responsible for maintaining phosphorous homeostasis within the body. This is important, as high levels of phosphorous intake can lead to bone, cardiovascular and kidney health problems, including CKD. If the function of the kidney is impaired, it results in the buildup of phosphorus in the blood. Therefore, it is essential to not eat foods containing high levels of phosphorous.⁷ Some low-phosphorous food choices include:

• Fresh fruits and vegetables
• Bread, corn and rice cereals
• Pasta
• Rice
• Fish⁸

Protein sources

Protein is essential for the body as it is involved in building muscle, repairing tissues and fighting infection.² It has also been found that protein sources can regulate phosphate levels and improve serum phosphorous levels resulting in helping with the preservation of kidney function. Your recommended daily protein intake will vary depending on various factors, including your health, body size and dietary habits.⁹ Some kidney-friendly protein choices include:

• Animal meat such as pork, beef, chicken, turkey or fish 
• Dairy products like milk, yoghurt and cheese
• Eggs
• Plant sources like beans, peaks, lentils, soy, tofu, nuts and seeds⁹

Antioxidant-rich foods

Antioxidant-rich foods contribute to kidney health by neutralising free radicals. When there is an excess of free radicals it can impact the levels of carbohydrates, protein, fat, and DNA, which in turn impacts kidney health. It was noted that foods rich in antioxidants provided beneficial properties to people suffering from CKD or hypertension.¹⁰ Some high antioxidant-rich foods include:

• Berries including cranberries, blueberries, strawberries, blackberries, and raspberries 
• Plums
• Garlic
• Apples
• Red bell peppers
• Red cabbage
• Red leaf lettuce¹¹

Healthy oils and fats

Healthy oils and fats have many benefits for our health, with one of them being kidney health - especially for patients suffering from CKD. Healthy fats are crucial for blood clotting, muscle movement, and reducing inflammation, and can also lower LDL cholesterol resulting in a lesser risk of heart disease and atherosclerosis. Some healthy oils that can be incorporated into daily dishes include avocado oil, canola oil, olive oil, sesame oil and sunflower oil.¹²

Balanced lifestyle

It is important to maintain a balanced lifestyle and only consume appropriate amounts of the recommended foods for kidney health. If in doubt, it is always advisable to consult a healthcare professional or dietician who can offer advice on how to keep a balanced diet and best incorporate different foods. Other precautions can also be taken to maintain kidney health and reduce the chances of getting CKD:¹³

Smoking 

Smoking negatively impacts general health by increasing the risk of cardiovascular disease, which can lead to CKD. Therefore, stopping smoking will reduce your chances of developing CKD.

Alcohol

Similarly, alcohol also has a negative impact on health by raising blood pressure and cholesterol levels. It is recommended not to exceed 14 units of alcohol weekly, which is equivalent to 6 pints of beer or 10 small glasses of wine.

Exercise 

Exercise is crucial to maintain good health as it can lower blood pressure and reduce the risk of kidney diseases. It is recommended to do at least 2 hours and a half of intensive exercise a week.¹³

Keeping hydrated

Furthermore, good hydration is crucial for kidney function as dehydration leads to concentrated urine containing excess minerals and waste products. This can lead to the formation of crystals, resulting in kidney stones and kidney disease. It is recommended by the NHS that women and men should drink 8 and 10 200ml glasses of water per day, respectively.

Drinking plenty of water helps the kidney to remove waste products including sodium and urea; however, it is important to remember that your optimal daily water intake can vary depending on weather conditions, how much you exercise, and health conditions (including pregnancy).¹⁴

Summary

To summarise, we all have two kidneys which play important roles in removing waste products from the body. Therefore, it is essential to make certain lifestyle choices to maintain good kidney health and prevent the development of kidney stones and other kidney diseases, including chronic kidney disease (CKD). 

One of the main factors which contribute to kidney health is diet. It is essential to maintain a balanced diet, ensuring that you include a variety of food products that contribute to good nutrition. These include consuming foods with low levels of sodium and phosphorous, high levels of potassium and antioxidants, protein and healthy oils and fats. There are various food items, especially fruits and vegetables, which contribute to good kidney health. 

Nevertheless, when incorporating these foods into your diet, it is important not to overexceed. It is always advisable to consult a healthcare professional or nutritionist who will be able to guide you and craft an appropriate meal plan to incorporate all these superfoods. Moreover, factors like smoking, alcohol and exercise also need to be regulated as they can impact general and kidney health.