Heart disease is the leading cause of death among kidney patients. Preventative measures such as eating a heart-healthy diet go a long way in minimizing this problem but are often at odds with the demands of a renal diet, especially in the latter stages of kidney diseases when diet is most likely to become restricted. Balancing these competing demands is not impossible, especially if you work actively with your nephrologist and renal dietitian.
Hypertension
Kidney patients invariably have high blood pressure or hypertension because the kidneys help regulate blood pressure. As they become progressively scarred, these organs sense less blood flowing through them, so they secrete a hormone that increases blood pressure. This increased pressure destroys even more of the filters in the kidney, setting up a vicious cycle. Patients often take four or five different medications to control this problem. Eating a low-sodium diet may not make hypertension go away, but it helps keep blood pressure as low as possible so that the drugs can work effectively.
Low-Sodium Diet
Both heart and kidney patients are urged to keep their total sodium intake below 1,500 mg per day. Avoiding frozen meals and most soups is a good first step. Exercising caution when eating out is important. Indian cooking that relies on a wealth of spices can be helpful. Chinese foods that rely on soy sauce and black bean paste are often prohibitively high in sodium.
Potassium Restriction
The concentration of potassium on either side of the membrane of nerve cells makes it possible for nerves to fire. Since this activity is essential to sustain life, healthy kidneys keep potassium levels within a narrow range by filtering excess potassium into the urine. Damaged kidneys are unable to do this effectively so potassium levels often creep up, which in turn, causes nerves to misfire and leads to irregular heart beats and even heart attacks. Restricting dietary potassium is one way patients can prevent this from happening.
Conflict
A heart-healthy diet includes a wealth of fruits and vegetables. Eating these may not be possible if you have to restrict potassium intake because many fruits and vegetables such as apricots, bananas, mangoes, squash, figs, carrots, celery, oranges and tomatoes have prohibitively high levels of potassium for some kidney patients. To get around this dilemma, nephrologists often prescribe special renal vitamins that don't have potassium.
Protein
Kidney patients who are on dialysis are often advised to eat more protein. This is necessary because dialysis removes important amino acids from the blood. However, patients need high-quality protein that is low in cholesterol and potassium, which rules out most red meats and eggs. Good sources of protein for dialysis patients include fish, chicken and egg whites.
Warning
Patients should never change their diet without consulting their nephrologist. All too often, patients act rashly and embark on unnecessarily restrictive or ill-considered diets that can aggravate the problem. Restricting potassium is quite pointless unless potassium levels are elevated. Likewise, a low-sodium diet requires regular monitoring of blood pressure. Restricting protein --- or eating too much protein or the wrong type of protein can have hazardous effects. Working together with your nephrologist, you can optimize a diet that is best for your particular situation.
References
- National Kidney Foundation: Chronic Kidney Disease (CKD)
- DaVita: Potassium and Chronic Kidney Disease
- DaVita: Sodium, the Heart and Kidney Disease
- DaVita: Dietary Protein and Chronic Kidney Disease (CKD)
- National Institutes of Diabetes, Digestive and Kidney Diseases: High Blood Pressure and Kidney Disease
