May 25, 2010 > Kidney Disease and Nutrition
Kidney Disease and Nutrition
Learn How Changes in Your Diet Can Help Protect Your Kidneys
According to the National Kidney Foundation, approximately 26 million adults in the Untied States have chronic kidney disease, and millions of others are at risk. As kidney disease progresses, the kidneys lose their ability to remove wastes and fluids from the body and to regulate various chemical and mineral levels in the blood. If kidney disease gets worse, it may eventually lead to kidney failure that requires dialysis or a kidney transplant to save the patient's life.
Fortunately, early detection and treatment of kidney disease - including specialized nutrition therapy - can help in managing the complications of chronic kidney disease.
"People need to become more aware of kidney disease," says Dr. Jeanie Ahn, a nephrologist (kidney specialist) at Washington Hospital. "Chronic kidney disease is defined as kidney function that is less than 60 percent of normal for longer than three months. Unfortunately, kidney disease usually doesn't produce any symptoms until the condition has progressed well beyond the early stages, so people with chronic kidney disease often don't realize they have it."
To help people in the community learn more about kidney disease and nutrition, Washington Hospital is sponsoring a free Health & Wellness seminar featuring Dr. Ahn and registered dietitian Cecillia Sun, who specializes in nutrition therapy for patients with kidney disease. The seminar is scheduled for Tuesday, June 1 from noon to 2 p.m. in the Conrad E. Anderson, M.D., Auditorium in the Washington West Building at 2500 Mowry Avenue in Fremont. Register online at www.whhs.com.
Risk Factors and Screenings
"The two primary risk factors for kidney disease are uncontrolled diabetes and high blood pressure - also called hypertension," Dr. Ahn notes. "Obesity also can be a risk factor because it can contribute to both diabetes and high blood pressure. Hispanics and African Americans are more at risk for kidney disease than other ethnic groups."
Other factors that may affect kidney function include:
* Immune system disorders such as Lupus
* Inflammatory kidney disease (glomerulonephritis)
* Inherited diseases such as polycystic kidney disease, which causes large cysts to form in the kidneys
"Damage to the kidneys caused by diabetes is called diabetic nephropathy," Dr. Ahn explains. "In addition to damaging the blood vessels in the kidneys that filter waste products from the blood, high blood sugar from uncontrolled diabetes directly enters the cells of the kidneys, eventually causing them to lose function."
High blood pressure also can damage the kidneys' blood vessels. That can be a vicious circle, because chronic kidney disease can also cause high blood pressure.
"People can get chronic kidney disease at any age, so it's important to have screenings for kidney disease as part of your regular physical exams," Dr. Ahn advises. "Those screenings become more important as you grow older because your risks increase as you age. People with a family history of kidney disease, diabetes, high blood pressure or obesity should be especially diligent about being screened regularly for kidney disease."
Screening involves testing for protein in the urine and blood tests for substances called urea and serum creatinine. An overall index of kidney function is the glomerular filtration rate (GFR), which a doctor can calculate from the results of the serum creatinine test along the patient's age, race, gender and other factors.
"Because symptoms often don't appear until the condition is quite advanced, regular screenings are key to diagnosing kidney disease and managing its complications," Dr. Ahn says. "People with severe kidney disease may experience symptoms such as fatigue, anemia, lack of appetite, insomnia and a general sense of malaise. Blood and protein in the urine and swelling in the feet and ankles - called edema - could be signs of glomerulonephritis."
The Role of Nutrition
"Most people with kidney disease need to limit the amount of salt in their diet," says Ms. Sun, who works at Washington Hospital and a dialysis clinic that provides both in-center and home kidney dialysis services. "A low-sodium diet can help control high blood pressure, which is one of the major causes of kidney disease.
"Some patients also may benefit from limiting the intake of protein and minerals such as potassium, phosphorus and calcium, since damaged kidneys cannot filter out excess wastes," she adds. "Patients with diabetes also need to maintain good control of their blood sugar levels. Controlling your weight is important, too, since it can be a contributing factor in both high blood pressure and diabetes."
Ms. Sun offers several suggestions for ways people can change their diets to protect the kidneys:
* Achieve and maintain a healthy weight by controlling meal portion sizes - when you "super size" a meal, you may also "super size" your body.
* If you have a history of diabetes, manage your blood sugar with the help of your doctor and dietitian.
* Avoid and limit your intake of table salt and salty processed foods such as luncheon meats, Spam, sausage and bacon to keep blood pressure at the optimal level of 120/70.
* Increase your physical activity, which helps burn excess calories and fat, and keeps your weight down.
* Read food labels to look for the levels of cholesterol, saturated fats and total fats, as well as for "hidden" sodium that may be listed as monosodium glutamate (MSG) or disodium phosphate.
"The nutritional needs of patients with kidney disease can be very individualized," Ms. Sun explains. "For example, in Stages 1 and 2, patients may only need to control their blood pressure and/or diabetes. With stages 3 and 4, they may also benefit from a diet with lower intake levels of protein and minerals. In Stage 5, however, most patients will require dialysis, and they actually need more protein in their diet. They also need to limit their intake of dietary sodium, potassium, phosphorus, calcium and fluids.
"People with kidney disease can often benefit from working with a registered dietitian who can help them make better choices," she adds. "It also can be valuable to consult an endocrinologist if you have diabetes, and a nephrologist who can help you delay the progression of kidney disease."
Learn More at Upcoming Seminar
To register for the June 1 seminar, or to get more information about upcoming Health & Wellness seminar topics, visit www.whhs.com and click on the links under "Upcoming Seminars." For more information about nutrition and kidney disease, visit the web site of the National Kidney Foundation at www.kidney.org and click on the link for "Nutrition, Diet" under the "Kidney Disease" heading.