The kidneys are small organs in the lower abdomen which play an important role in the overall body health. Some foods may boost kidney performance while others may put stress on them and cause harm.
The kidneys filter out blood waste products and send them out into the urine from the body. They do have a duty to control the fluid and electrolyte levels.
With no outside help the kidneys carry out these activities. Several conditions might affect their ability to function, such as diabetes and high blood pressure.
In the end, kidney damage can lead to chronic kidney disease ( CKD). As the authors of an article published in 2016 note, diet is the most significant risk factor for death and disability associated with CKD, making dietary changes a key part of treatment.
Following a healthy diet plan for the kidneys can help the kidneys function properly and prevent damage to those organs. While certain foods usually help a healthy kidney, they are not always appropriate for people with kidney disease.
Water
Water is the body’s most essential drink. The cells transport toxins into the bloodstream using water.
The kidneys then use water to flush out those toxins and produce the urine that takes them out of the body.
Drinking whenever a person feels thirsty can support these functions.
Fatty fish
Salmon, tuna, and other cold-water, high in omega-3 fatty acids, fatty fish can make a beneficial addition to any diet.
The body is unable to make omega-3 fatty acids, which means they have to derive from the diet. Fatty fish constitute a great natural source of these healthy fats.
As the National Kidney Foundation reports, omega-3 fats can lower blood fat levels and even reduce blood pressure a little bit. As high blood pressure is a risk factor for kidney disease, it can help protect the kidneys by finding natural ways to lower this.
Sweet potatoes
Sweet potatoes are similar to white potatoes but their excess fiber can cause them to break down more slowly, causing insulin levels to spike less. Sweet potatoes also contain vitamins and minerals such as potassium, which can help balance the sodium levels in the body and reduce its kidney effects.
Because sweet potato is a high-potassium food, however, anyone who has CKD or is on dialysis may wish to limit their consumption of this vegetable.
Dark leafy greens
Dark leafy greens, such as spinach , kale, and chard, are dietary staples containing a wide range of vitamins, fibers, and minerals. Many also have protective compounds, for example antioxidants.
These foods, however, also tend to be high in potassium, so they may not be suitable for people with restricted diets or those with dialysis.
Berries
A perfect source of many beneficial nutrients and antioxidant compounds are dark berries, which include strawberries, blueberries, and raspberries. These may help to prevent damage to the cells in the body.
Berries are probably a better option to satisfy a sweet craving than other sugary foods.
Apples
An apple is a healthy snack that contains pectin, an important fiber. Pectin can help to reduce some kidney damage risk factors , such as high blood sugar levels and cholesterol.
Sometimes, apples will satisfy a sweet tooth too.
Foods to avoid
There are some things that people can avoid if they want to improve their kidneys health or prevent harm to those organs.
These include the following:
Phosphorous-rich foods
Too much phosphorus can put your kidneys under stress. Research has shown that there is a link between high intakes of phosphorous and an increased risk of long-term kidney damage.
However, there is insufficient evidence to prove that phosphorous causes this damage, so more research is needed on this subject.
For people looking to reduce their intake of phosphorous, high in phosphorous foods include:
- meat
- dairy products
- most grains
- legumes
- nuts
- fish
Red meat
Some types of protein can be more difficult to process for the kidneys, or for the body in general. These encompass red meat.
Initial research has shown that people who eat much red meat have a higher risk of end-stage kidney disease compared to those who eat less red meat. Nevertheless, more studies are needed to investigate this risk.
Foods for people with CKD
Although the above foods may generally support a healthy kidney, they are generally not the best choices for people with CKD.
Doctors can place most people with CKD on a special diet to prevent minerals being absorbed by the kidneys, such as sodium, potassium , and phosphorus.
The National Institute of Diabetes and Digestive and Kidney Diseases recommend that people with CKD eat less than 2,300 milligrams of sodium every day.
As CKD progresses , people may also need to limit their intake of phosphorus, since this mineral can build up with this disease in people’s blood.
It is also important for people with CKD to choose the right amount of potassium, because problems can arise when potassium levels get too high or too low.
People with CKD should aim to eat healthy foods which are low in these minerals but which still provide other nutrients to the body.
Reducing their protein intake can also be essential for people with CKD, and include only small amounts of protein in their meals. When the body uses protein it transforms into waste which must then be filtered out by the kidneys.
Eating a diet lower in protein that, as a 2017 study states, protect against CKD complications such as metabolic acidosis, which occurs as kidney function deteriorates. Researchers indicated that eating a diet that is rich in fruits and vegetables and low in protein could help to reduce those risks.
People with CKD may work with a dietitian directly to develop an effective diet plan that meets their needs.
Cabbage
Cabbage is a leafy vegetable which can be of benefit to people with CKD. It is relatively low in potassium and very low in sodium, but it also contains many useful vitamins and compounds.
Red bell peppers
Besides being very low in minerals like sodium and potassium, red bell peppers contain helpful antioxidant compounds that can protect the cells against damage.
Garlic
Garlic is an excellent alternative for people with CKD to season with. This can provide a more fulfilling, full flavor to other foods which can reduce the need for extra salt. Garlic provides a range of health benefits too.
Cauliflower
Cauliflower is a versatile vegetable intended for CKD people. It makes a good replacement for foods like rice, mashed potatoes and even pizza crust, with the right preparation.
Even, couliflower provides a number of nutrients without offering too much sodium , potassium or phosphorus.
Arugula
Many greens may need to be avoided by people with CKD but arugula can be a great replacement. Arugula is normally lower in potassium than other greens but it still contains fiber and other nutrients that are beneficial.
Berries
The fruits below can be a healthful sweet snack for people with CKD:
- cranberries
- strawberries
- blueberries
- raspberries
- red grapes
- cherries
Olive oil
Olive oil is perhaps the best cooking oil due to the type of fat it contains. Olive oil is high in oleic acid, a polyunsaturated fatty acid which can help to reduce body inflammation.
Egg whites
Eggs are a simple protein but the yolks in phosphorous are very high. People with CKD may use only the egg whites to make omelets or scrambled eggs.
Foods for people with CKD to avoid
Some foods can be difficult for the body to handle for people with CKD, which may place more stress on the kidney. Including:
- white potatoes
- red meat
- dairy products
- sugary beverages
- avocado
- bananas
- canned foods
- pickled foods
- alcohol
- egg yolks
People who are looking to protect their kidneys against future damage might also want to consider eating these foods in moderation.
Summary
The kidneys play an important role in blood filtering and the removal of waste products in urine. Many foods can help support a kidney that is already healthy and prevent damage to that organ.
However, people with chronic kidney disease will need to follow a different set of dietary rules to prevent further damage to their kidneys.
It is always best to talk to a licensed dietitian before proceeding with any changes in diet.
