If you’ve never been tested for kidney disease, make an appointment now. An estimated 26 million American adults have chronic kidney disease (CKD), and millions more have a high risk of getting it. Yet most people with CKD don’t realize that their kidneys are failing.
Important warning: CKD usually causes no symptoms until about 75% of kidney function is lost. At that point, you’ll probably need dialysis—and possibly a kidney transplant—to survive. That’s why everyone should have yearly kidney-function tests, starting at about age 60 or earlier if you are at risk for kidney disease.
Your two kidneys are the body’s filters. Together they filter more than 40 gallons of blood daily, removing wastes that are then secreted in the urine. CKD is caused by ongoing damage to the nephrons, the kidneys’ filtering units. When CKD reaches an advanced stage, you will have a dangerous buildup of fluid, electrolytes and wastes in your body.
But you may be able to halt the progression of CKD with timely intervention. The blood tests for CKD—serum creatinine and glomerular filtration rate—are simple and inexpensive. If you have CKD, your doctor likely will treat the underlying causes and put you on a diet that stabilizes kidney function and slows or stops further damage. There are no studies to prove that this diet will prevent CKD, but many of the recommendations, such as consuming less salt and fewer soft drinks, offer health benefits for us all…
Less protein overall. The average American adult gets about 0.55 grams (g) of protein for every pound of body weight. A 176-pound man, for example, probably consumes at least 96 g of protein a day. That’s about 33% too much for someone with early-stage chronic kidney disease—and about double the amount recommended for someone with advanced disease.
A high-protein diet delivers too much nitrogen, which stresses the kidneys and can accelerate progression of CKD. Most patients are advised to limit their daily protein to 0.34 g per pound of body weight—for a 176-pound man, that is about 60 g of protein.
How much protein are we talking about? Examples: A five-ounce serving of salmon has 36 g of protein…a three-ounce serving of lean chicken has 28 g…one cup of pinto beans has 11 g…and a large egg has 6 g.
My advice: Limit your total protein from animal foods to about 50%. Get the other half from high-protein plant foods, such as tofu, grains and beans. Plant-based proteins are easier on the kidneys, and these foods also provide important fiber, nutrients and antioxidants.
Watch for phosphorus. This is an important mineral for bone health, but it can rise to dangerous levels in people with CKD. Too much phosphorus can cause bone pain, bone thinning and an increased risk for fractures. It also increases the risk for heart disease.
The body absorbs relatively little of the organic phosphorus in meats, vegetables and other natural foods. However, you’ll absorb up to 100% of the inorganic phosphorus that’s used in preservatives in packaged foods, fast foods and processed meats.
Helpful: To avoid products that contain phosphorus, look for any form of “phos” on the label—sodium phosphate, phosphoric acid, calcium phosphate, etc.
Leach out potassium. Like phosphorus, the mineral potassium can rise to unsafe levels. Patients with CKD should limit their daily consumption to 2,000 mg to 2,700 mg.
Many fruits and vegetables, such as bananas, oranges, potatoes, beets, Brussels sprouts and dark, leafy greens are high in potassium. One potato, for example, has nearly 900 mg.
You can use a leaching process to reduce the potassium in some high-potassium vegetables before using. Peel and place the vegetables in cold water so that they don’t darken…slice the vegetables about one-eighth-inch thick…rinse them in warm water…then soak them in warm water for at least two hours, using 10 cups of water for every one cup of vegetables.
A two-hour soak is enough for most vegetables, but root vegetables such as potatoes or beets need to soak longer, preferably overnight. If soaking longer, change the water every four hours.
Or choose lower-potassium foods, such as apples, asparagus, celery, green beans, grapes and blueberries.
Limit dairy. People with CKD may need to limit their dairy intake. Milk, cheese and other dairy foods are high in potassium and phosphorus. You can get healthy amounts of calcium from other foods, such as soy milk or almond milk.
Get much less salt. Too much sodium can increase blood pressure along with kidney damage and cause swelling of the extremities.
The average American consumes more than 3,000 mg of sodium daily. Lower that to 1,500 mg to 2,000 mg, especially if you have CKD. Because packaged/prepared foods often are high in sodium, get in the habit of reading labels. It’s also helpful to rinse certain prepared foods (such as canned vegetables) in water. And use herbs and spices to bump up the flavors of foods instead of using table salt.
Don’t depend on salt substitutes. Most contain potassium or other ingredients that can be hard on the kidneys.
Give up soft drinks. Studies have shown that people who drink more than a few sodas a week may be more likely to get kidney disease. If you have been diagnosed with CKD, soft drinks—particularly “dark” sodas—are a problem. They’re high in phosphorus as well as sodium.
My advice: I advise everyone to give up sodas (including diet beverages and “clear” soft drinks) and switch to drinking water instead. It dilutes the blood and puts less strain on the kidneys. Most people should drink about 64 ounces of water daily.
