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Want to know what foods are bad for kidneys? Keep reading to find out more.
Humans have two kidneys on either side of their bodies. Kidneys are bean-shaped and dark-brownish in color, 10-12 cm in length, and 5-7 cm in width. The kidneys weigh roughly 120 to 170 grams in a healthy adult human, which helps perform many essential functions.
The kidneys are responsible for the following:
- Filtering blood
- Excreting waste through urine
- Synthesizing hormones
- Keeping the body’s mineral balance
- Keeping fluid equilibrium
Uncontrolled diabetes and high blood pressure, as well as alcoholism, heart disease, HIV, and hepatitis C1, are all risk factors for kidney disease.
When the kidneys are injured or fail to work effectively, fluid can collect in the body, and waste can accumulate in circulation.
However, eliminating or restricting specific foods from your diet may help reduce waste product accumulation in the blood, enhance renal function, and minimize damage.
1. Limiting Diet According to Kidney Diseases
The dietary restrictions vary depending on the stage of kidney disease. So, if you have kidney damage, you should know what foods are bad for the kidneys.
For example, people with early stages of chronic kidney disease will have different dietary limits than those with kidney failure or end-stage renal disease.
Although, dialysis patients with late-stage kidney disease have a variety of dietary restrictions. Most of those with late or end-stage kidney disease will need to follow a kidney-friendly or renal diet to avoid accumulating substances in the blood.
The kidneys of people with chronic renal disease2 cannot eliminate excess sodium, potassium, or phosphorus. As a result, they’re more likely to have high levels of these minerals in their blood.
A kidney-friendly diet limits sodium to under 2,300 mg per day and your potassium and phosphorus intake.
If you have kidney disease, your health care professional will suggest to you what foods are bad for kidneys that you should likely avoid.
While dietary limitations vary based on the stage of kidney disease, what should you consume, and what foods are bad for kidneys? Those with kidney disease should limit the following nutrients:
1.1 Sodium-rich Foods
Sodium is present in most foods, ubiquitous salt, but damaged kidneys cannot filter out excess sodium, causing blood levels to increase.
According to experts, limit sodium intake to fewer than 2,000 mg daily.
1.2 Potassium-rich Foods
Potassium has several vital functions in the body; however, people with kidney disease must limit their potassium intake to avoid high blood levels.
Potassium levels should not exceed 2,000 mg per day.
1.3 Phosphorus-rich Foods
Phosphorus, a mineral found in many foods, cannot be removed by damaged kidneys if consumed in large amounts. These high amounts can affect the body.
Most patients’ daily phosphorus intake is limited to 800–1,000 mg.
Protein is another nutrient patients with renal dysfunction may need to limit since their kidneys cannot filter waste products produced by protein metabolism.
According to research, end-stage renal disease patients on dialysis, a blood-filtering and-cleaning procedure, have higher protein requirements.
People with kidney failure should work closely with their doctor or a kidney dietitian to assess their specific dietary needs based primarily on laboratory tests.
2. What Foods are Bad for Kidneys?
So, let us discuss what foods are bad for the kidneys that you should likely avoid if you’re on a renal diet.
The following are 11 foods that are harmful to patients with renal disease.
2.1. Dark-colored Soda
Dark-colored sodas are not ideal for people with kidney disease. People on a renal diet should avoid dark sodas since they contain phosphorus, which many food and beverage makers use to prevent discoloration, extend shelf life, and enhance flavor.
Healthy kidneys can eliminate extra phosphorus from your blood, but this isn’t the case when you have kidney disease.
However, according to research, this additional phosphorus absorbs into the body more readily than natural, animal-based, or plant-based phosphorus.
Most black sodas are believed to have 100-200 mg of phosphorus per 400 mL serving. The amount of phosphorus in this addition varies depending on the type of soda. In contrast to natural phosphorus, sodas have a different form of phosphorus than foods.
According to research, additive phosphorus is not bound to protein and instead exists as a salt; it is more easily absorbed into the bloodstream.
According to research, having high blood phosphorus levels for an extended period can increase the risk of cardiovascular disease, bone thinning, and premature mortality.
According to a study, high blood sugar for an extended period can harm the neurological system, cause kidney failure and increase the risk of heart disease.
Choose a low-sugar, low-phosphorus beverage, such as water, natural sweeteners, or sparkling water flavored with sliced fruits or vegetables, instead of these dark-colored sodas.
According to the USDA food database, a 32-ounce (984 g) can of soda has 88.6 mg of phosphorus. So, people with kidney disease and diabetes should know what foods are bad for the kidneys; and avoid dark sodas and other high-phosphorus, high-sugar beverages.
2.2. Oranges and Orange Juice
While oranges and orange juice are good sources of vitamin C content, they’re also high in minerals such as potassium.
A raw orange juice (100 grams) provides 200 mg of potassium. However, USDA data shows 232 mg of potassium in a large orange (140 mL).
Oranges, orange juice, and other sugar-sweetened beverages high in potassium must be avoided or limited if you have kidney disease and diabetes.
Furthermore, these drinks are often abundant in processed sugar, which can increase blood sugar. This is significant because diabetes affects your body’s capacity to absorb sugar effectively, and high blood sugar levels over an extended period can cause various health problems.
So, after knowing what foods are bad for the kidneys? Try some foods that are good for your kidneys- grapes, apples, cranberries, or their juices instead of orange, as they have lower potassium contents.
2.3. Potatoes and Sweet Potatoes
Potatoes and sweet potatoes are potassium-rich foods, which can be a concern for those with kidney disease, especially those with late-stage kidney disease.
Fortunately, several high-potassium foods, such as potatoes and sweet potatoes, maybe soaked or leached to lower their potassium level dramatically.
According to one research, chopping potatoes into small, thin slices and boiling them for at least 10 minutes can lower potassium concentration by roughly 50%. This approach is known as potassium leaching; nevertheless, it is crucial to note that the potassium content is not eradicated.
According to another study, potatoes soaked in water before cooking have an even lower potassium content than raw potatoes, which is suitable for people with kidney disease.
Considerable amounts of potassium can still be present, so it’s best to eat them in moderation if you have renal disease.
2.4. Whole Grain Bread
For people with kidney damage, picking the ideal bread might be challenging. Usually, whole grain bread is suggested over refined white flour bread for healthy people.
Whole grain bread may be more nutritious due to its higher fiber content. However, white bread is usually recommended over whole wheat bread on a renal diet due to its lower phosphorus and potassium levels.
The more fiber and whole grains in the bread, the higher the phosphorus and potassium content.
Eating one slice of whole-grain bread instead of two can reduce your potassium and phosphorus intake without completely giving up whole-grain bread.
It’s advisable to check bread nutrition labels, opt for a lower sodium variety if possible, and keep track of your serving size.
2.5. Canned Vegetables
Canned vegetables and beans are often purchased because of their low cost and convenience.
However, most canned foods are high in sodium, as salt is added as a preservative to increase their shelf life and enhance flavor. Due to the amount of sodium found in vegetables, it’s often recommended that those on a renal diet avoid or limit their consumption.
It’s usually advisable to avoid high-sodium versions or ones labeled “no salt added” to limit sodium intake.
Furthermore, according to research, draining and rinsing canned vegetables can reduce sodium levels by 33–80 percent, depending on the product.
2.6. Dried Fruits
Dried fruits are made by removing water from fresh fruits through various processes; their nutrients are concentrated, including potassium and sugar. Therefore, the potassium content of dried fruit, including dates, apricot, prunes, and raisins, is exceptionally high and should be avoided by people on a renal diet.
These are not suggested for people with chronic kidney disease or diabetes because they are high in sugar and nutrients like potassium.
According to a study, if you have kidney disease, your body can’t remove potassium properly, leading to increased blood potassium levels, also known as hyperkalemia. This condition can lead to drowsiness, joint pain, bone disease, cardiac difficulties, and even fatality if left untreated.
For example, 100 grams of dried apricots contain around 1160 mg of potassium4, according to data given by USDA. Additionally, 100 grams of prunes provides 732 mg of potassium; moreover, just 100 grams of dates provide 696 mg of potassium.
2.7. Snack Foods
Snack foods or ready-to-eat foods such as chips, crackers, and pretzels are typically lacking in nutrients and high in salt and refined sugar, making them unsuitable for kidney patients and diabetics.
Additionally, ready-to-eat foods, such as potato chips, also contain a lot of potassium or phosphorus, whether naturally occurring or due to additions.
For example, according to USDA, a 100-gram single-serving bag of potato chips contains 1200 mg of potassium, 527 mg of sodium, and 153 mg of phosphorus.
Limit or avoid your intake of these foods as part of any healthy foods, especially if you have health conditions such as kidney disease and diabetes. Instead, experiment with nutrient-dense kidney-friendly foods.
Eating more than the recommended portion size of these foods is easy, often leading to an even greater salt intake than intended.
2.8. Packaged Foods
Packaged foods, instant, prepared foods, and fast food is usually the most heavily processed and thus contain the most sodium and low nutrients in the diet. This is one reason to limit these foods on a renal diet, and they aren’t the best option for someone with diabetes and kidney problems.
Instant noodles, frozen pizza, frozen boxed foods, and other pre-cooked meals are just a few examples of these foods.
Keeping sodium intake as suggested may be difficult if you eat highly processed foods regularly.
2.9. Pickles, Olives, and Relish
Pickles, processed olives, and relish are examples of pickled foods. They are typically high in sodium due to the curing or pickling process and should be avoided on a renal diet.
For example, a 1-ounce (28g) pickle can contain 245 mg of sodium. Likewise, there is 122 mg of sodium in 1 tablespoon (15g) of sweet pickle relish. Processed olives are also salty since they’ve been cured and pickled to make them taste less tart.
A 100-grams of pickled olives provide about 1556 mg of sodium, a significant portion of the daily amount in only a small serving.
However, several grocery shops provide low-sodium pickles, olives, and relish, with less salt than regular ones.
Although the low-sodium options can be high in sodium, limit your servings.
Dairy foods are high in vitamins and minerals, including phosphorus, potassium, and protein. For example, 100 grams of whole milk provides 91 mg of phosphorus and 143 mg of potassium.
However, when combined with other phosphorus-rich foods, excessive dairy consumption can harm bone health in those with kidney disease.
According to a study, too much phosphorus 5intake can induce phosphorus accumulation in the blood, which can remove calcium from bones if kidneys are damaged. Over time, this can thin and weaken your bones, increasing your risk of bone-breaking or fracture.
Protein is also abundant in dairy products. A 100-gram serving of whole milk has 3.2 grams of protein. Reducing dairy consumption may be necessary to minimize the deposit of protein waste in the blood.
Furthermore, rice and almond milk contain less potassium, phosphorus, and protein than cow’s milk, making them a good substitute for dairy while following a renal diet.
2.11. Alcoholic Drinks
When the body is dehydrated, the drying effect can interfere with the proper function of cells and organs, including the kidneys, which filter out toxic substances.
Alcohol impairs kidney function and reduces the ability of the kidneys to filter blood. Alcohol also inhibits the body’s ability to regulate water and electrolytes. Moreover, high blood pressure affects the kidneys, and excessive alcohol consumption can raise blood pressure.
In this scenario, a person may seek the advice of a renal dietitian to learn what foods are bad for kidneys and how to create the best healthy eating plan for themselves.
3. Kidney-Friendly Diet
After discussing what foods are bad for the kidneys, let us discuss kidney-friendly foods.
Your diet should be customized to your renal disease stage. When you have chronic kidney disease in its early stages (Stages 1 and 2), there are fewer restrictions on what you should consume and what foods are bad for your kidneys.
Still, if the condition worsens (Stages 3, 4, and 5), your healthcare professional may advise you to limit it. People should choose foods with lower salt, potassium, and phosphorus levels should be preferred.
There are several of them:
3.1 Foods Low in Potassium
Potassium is a mineral that is present in foods. Healthy kidneys balance the blood’s potassium levels, but those with chronic kidney disease may need to limit their intake after consultation with their doctor:-
- Summer squash
- White bread
- White rice
3.2 Low Phosphorus Foods
Healthy kidneys maintain the appropriate amount of phosphorus in your body. But if you have kidney damage, you should know what foods are bad for your kidneys, like high-phosphorus foods. Ask your doctor or renal dietitian if you need to limit phosphorus.
- Corn or rice cereals and cream of wheat
- Unsalted popcorn,
- Italian, French, or sourdough bread
- Some light-colored sodas and lemonade
3.3 Limit Fluid
You may need to restrict water and beverages if you have renal disease since damaged kidneys cannot eliminate excess fluid as effectively as they should. Too much fluid in your body can lead to high blood pressure, edema, and cardiac arrest.
To reduce fluid intake, limit your intake of soups, ice cream, gelatin, and many fruits and vegetables, which are high in water.
4. In The End
Dietary restrictions, such as what foods are bad for kidneys and how much of each nutrient you should consume, will vary depending on your stage of renal disease.
If you have renal disease, lowering your potassium, phosphorus, protein, and sodium intake can help you manage your overall condition. Foods rich in salt, potassium, protein, and phosphorus should probably be reduced or avoided.
Regardless, reducing these nutrients can help you better manage the disease and lower the chance of future complications. Working with a healthcare practitioner and a renal dietitian can help create a renal diet adapted to your needs.
Let’s hope you now have a clearer understanding of what foods are bad for the kidneys.
If you still have questions about what foods are bad for kidneys, talk to your health professional before making any changes in your daily exercise routine.
Please leave a comment below if you have any concerns regarding this blog. Thank you very much, and have a fantastic day!
If you liked this one, here’s something more to read.
Q. Does every protein harm the kidneys?
No, however a high protein diet and excessive protein intake, particularly from red meat, can put a strain on the kidneys. Choose lean protein sources, and for individualized guidance, talk to a healthcare expert.
Q. Do some fruits and vegetables need to be avoided for the health of the kidneys?
If you have kidney problems, you should consume some high-potassium fruits and vegetables, such as potatoes, tomatoes, bananas, and oranges, in moderation. Potassium content can be reduced through cooking or leaching.
Q. How do the kidneys respond to a high phosphorus diet?
Extra phosphorus can weaken bones, hasten kidney damage, and worsen renal disease consequences. Dairy goods, processed meats, and colas are some examples of foods high in phosphorus.
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