Your kidneys are vital to your overall health and wellbeing. They are responsible for filtering extra fluid, waste products and toxins from your body. They also play a role in regulating blood pressure, red blood cell production and vitamin D metabolism.

However, incidences of kidney disease are on the rise. In many cases people aren't aware there is a problem until their kidneys have been significantly damaged. A healthy diet is one way you can prevent or treat kidney disease. Try to fill up on foods that boost kidney function and avoid those that promote disease.

Beneficial foods for kidney function

Fish
While it's important to reduce protein intake to protect kidney function, and fish is a rich source of protein, it also provides other benefits. Many types of fish are less fatty than red meats, pork or poultry and for this reason are a more beneficial form of protein. However, the fatty fish such as salmon, mackerel, tuna and herring are chock full of omega 3 essential fatty acids that improve cardiovascular health, while other meats contain high levels of saturated fats, which are considered dangerous. When you have kidney disease you are more at risk for cardiovascular disease. Research also shows that fish can fight obesity, which is a leading cause of type 2 diabetes — a major cause of kidney disease.

Low-potassium Foods
Potassium is another mineral, along with sodium and phosphorus, which you should reduce to improve kidney function. However, potassium is present in a wide variety of foods, and its content is not as noticeable as sodium or sugar, for instance, because you cannot taste it.

Try to stick to low-potassium foods such as asparagus, cabbage, cauliflower, cucumbers, black berries, grapes, peers, onions, summer squash and tangerines. Also, check food packages for potassium content.

Green Tea
This popular beverage is rich in antioxidants that protect organs — including the kidneys — from free radical damage and infection. It may also prevent kidney stones, which can contribute to kidney damage.

According to the University of Maryland Medical Center in the U.S., green tea also has anti-inflammatory properties and improves cardiovascular health, such as reducing cholesterol levels and preventing atherosclerosis. It's also a healthy, natural diuretic and helps to remove excess fluid from your body, a function that's compromised when your kidneys aren't working efficiently.

Other Worthy Mentions
- Watermelon
- Asparagus
- Black beans
- Celery

Foods that Harm Kidney Function

Protein
Limiting your protein intake limits the amount of nitrogen-containing amino acids that need to be excreted in urine in the form of urea. When kidneys aren't functioning properly, these substances build up in your blood and damage the filtering blood vessels in the kidneys.

First, limit the amount of protein you eat in the form of meat and dairy products. Replace them with healthier sources such as soy, whole grains, fish, and on occasion low-fat poultry.

Processed and fast foods
These foods are packed with sodium, which you must restrict to boost kidney function and treat kidney disease. They're also usually rich in phosphates. Phosphates disrupt protein and nitrogen balances in the body and also affect bone health, which is already compromised when you have kidney disease because vitamin D metabolism is impaired.

Fatty foods
Kidney disease elevates cholesterol levels in the blood and your risk of cardiovascular diseases such as heart attack and stroke. Fatty foods also increase cholesterol and triglyceride levels. By increasing fat levels in your body, fatty foods promote weight gain and heighten your risk of developing diabetes, one of the leading causes of kidney disease.

As you can see, making some simple changes in your diet can go a long way in protecting your kidneys from damage, and nutritional supplements have even shown to reverse kidney disease.

Other Worthy Mentions
- Acidifying foods e.g. alcohol, red meat, sugar, wheat, dairy and food additives
- Sugar
- Dairy
- Gluten