As a kidney doctor, one of the most common questions I get is, “What should I eat to keep my kidneys healthy?” Not surprisingly, I tell my patients to eat plants. With plant-based foods being so beneficial for the prevention and treatment of so many other diseases, it should come as no shock that they are also good for your kidneys.
Preventing Kidney Disease
The best treatment is prevention, and nowhere is that truer than in kidney disease. Once your kidneys are gone, they are gone forever, leaving dialysis or transplant as the only options—and neither is as good as holding onto your own kidneys, which work to filter out excess water and toxins from the body to form urine.
The most common causes of kidney failure are diabetes and high blood pressure. Both conditions cause changes to the blood vessels and internal structures of the kidneys, reducing their function over time. The more uncontrolled your blood pressure or diabetes is, the more damage can be done to your kidneys. If you already have high blood pressure or diabetes, it is not too late: They can be controlled and even reversed by eating a plant-based diet. Foods such as fruits, vegetables, whole grains, beans, and lentils can treat diabetes and high blood pressure and thereby prevent damage to your kidneys.
Plant-based foods are rich in fiber and antioxidants that can directly lower your blood pressure, improve glucose levels, reduce total body weight, and lower inflammation—all of which play a role in kidney disease. There is even evidence that meat-based foods cause the production of a compound called TMAO, which has been shown to directly cause kidney disease. Animal-based foods often are rich in other components that can be harmful to kidney function, such as sodium, fat, acid, phosphate, and excess protein.
Treating Kidney Disease
If you already have kidney disease, the answer is the same: Eat plants! Plant foods can be beneficial for those with kidney disease in three important ways:
• Blood pressure: Kidney disease often raises blood pressure. Plant foods are naturally low in sodium and chloride (which raise blood pressure) and high in magnesium, calcium, potassium, and bicarbonate (which lower blood pressure). Research has shown that even the combination of amino acids found in animal foods raises blood pressure more than those found in plant foods. By eating plant foods, you may be able to control your blood pressure naturally and reduce your need for medications.
• Natural alkali: Plant foods are rich in natural alkali that prevent chronic acidosis, which is a common occurrence in patients with kidney disease. In some cases, acidosis can be so bad that patients take actual baking soda to return their blood to a natural pH. Low-pH (acidic) blood can worsen kidney disease. However, plant foods are pH neutral or alkaline and can prevent the worsening of kidney disease from acidosis. Why take pills when you can eat plants?
• Phosphate: Animal-based foods are high in bioavailable phosphate, which can raise blood phosphate levels and worsen kidney disease. Some people have phosphate levels so high that they need to take medications to bring them down. These medications can be reduced or eliminated by eating foods low in bioavailable phosphate (such as plants) and avoiding foods high in it (such as animal-based foods and sodas).
Protein and Potassium
Many patients worry about getting enough protein on a plant-based diet, especially those with kidney disease. However, multiple studies have shown that people eating a plant-based diet that includes a variety of fruits, vegetables, grains, and legumes have no trouble getting enough protein or amino acids. Patients only run into problems if they rely solely on a limited number of foods for their calories (for example, eating just apples and nothing else, day after day).
A word about potassium: High potassium levels can be fatal in patients with kidney disease and are a concern for patients eating plant foods, which are often rich in potassium. However, not all foods raise potassium to the same extent. For example, plant-based juices and sauces can raise potassium levels quickly and should be avoided or used with caution. Eating whole fruits and vegetables is generally safer, as they contain fiber, which helps eliminate potassium from the body with bowel movements. Plant foods also contain natural alkali, which can blunt the rise in potassium in the blood. If you have kidney disease and are considering transitioning to a plant-based diet, it is important to have your blood checked to monitor for high levels of potassium, at least initially, and to have physician supervision. If you have high levels of potassium, you may need to adjust your diet (reducing the use of tomato sauces, for example) or your medications to help with the transition. However, many patients with kidney disease have safely tolerated the transition to a plant-based diet and, more importantly, have greatly benefited from it.
Ready to get started? Check out Forks Meal Planner, FOK’s easy weekly meal-planning tool to keep you on a healthy plant-based path.