The two kidneys are beans, but much larger. About 1 million microscopic filters in each kidney get rid of waste products in the blood via urine. In addition to glomeruli, the kidneys consist primarily of blood vessels.
Over half of American adults currently 30-64 years of age are expected to develop chronic kidney disease, most of which is caused by atherosclerosis (hardening of the arteries). Because the kidneys are so vascular, they are particularly sensitive to atherosclerosis. Causal risk factors include hypertension, smoking, sedentary lifestyle, obesity, diabetes, high cholesterol, inflammation and a diet rich in animal products.
According to Dr. Michael Greger in his book “How Not to Die” and his website NutritionFacts.org, researchers have found three specific dietary components associated with a decrease in kidney function: animal protein found in meat, poultry, shellfish, eggs and dairy; animal fat; and cholesterol (all animal products including seafood contain cholesterol). Animal protein primarily damages the kidneys because it causes acidity and inflammation. A fourth substance that damages the kidneys are phosphate additives in cola drinks and meats used for color enhancement.
Renal function is determined by the following: serum (blood) creatinine, normal 1.22 or less; GFR (glomerular filtration rate), where normal is greater than 60. The results of these two kidney function tests are part of chemistry panels performed at doctors’ offices, hospitals and health fairs.
Another important test for kidney health is a urinalysis, which is not performed at health fairs due to collection and storage problems. Any protein in the urine is abnormal. The most sensitive test for urine protein is the ratio of microalbumin to creatinine, with the normal value being 7.5 or less in a female and 4.0 or less in a male.
If you have protein in your urine; an elevated microalbumin / creatinine ratio; a blood creatinine greater than 1.22 or a GFR of less than 60, you have chronic kidney disease that needs to be evaluated and treated (treatment involves treating risk factors for atherosclerosis in the second section). There are different degrees of chronic kidney disease. For example, a GFR between 15 and 29 is classified as severe, which means that it is heading in the direction of dialysis or kidney transplantation.
Now an illustrative patient story: AS is a man in his 70s who was referred to the Center for Disease Prevention and Treatment through Nutrition / Folkeklinikken by a friend of his. He presented on July 12 accompanied by his wife. For years, he had been on a high-sodium diet recommended by doctors for low blood pressure (note that sodium not only raises blood pressure but also directly damages the endothelial organ system that leads to our arteries). He has also been on the Paleo diet for over three years, which is high in kidney-damaging animal protein. He was diagnosed with chronic kidney disease a year before last month’s visit, after which a kidney ultrasound was normal (usually the pathology causing chronic kidney disease does not show an ultrasound). He was not advised on diet, but even made the decision to increase his daily intake of animal protein even more.
AS’s laboratory results on June 23 showed a serum creatinine of 2.63 and a GFR of 25, which put him in the severe class of chronic kidney disease, heading towards dialysis or kidney transplantation. His total cholesterol was 232 (“normal” was <200 but ideally <150); LDL or bad cholesterol 173 ("normal" <100 but ideally <50).
The patient was encouraged to go on a total plant-based, whole food, without sugar, salt or added oil. With the support of his wife, he did so. Repeat laboratory on July 31, after two weeks on diet, showed a creatinine of 1.55; GFR of 46; total cholesterol 181; and LDL 132. So just with these dietary changes for two weeks – even though his kidney function is not normal and his cholesterol is not ideal – he is out of the woods on both issues. Hopefully over time, both issues will improve further and possibly resolve.
Unfortunately, the medical system in the United States is not aimed at preventing or treating diseases through simple measures such as lifestyle changes. Medical schools fail to teach students about the power of unhealthy foods to cause illness; or of healthy food to prevent, treat and often reverse disease. And most GPs are not aware of the extensive medical literature out there that supports food as medicine.
Dr. Feinsinger is a retired family physician with a special interest in disease prevention and reversal through nutrition. Free services through the Center For Prevention and The People’s Clinic include: one-hour consultations, shop-with-a-doc at Carbondale City Market, and cooking classes. Call 970-379-5718 for an appointment or email gfeinsinger@comcast.net.
