How to Protect Your Kidneys

Sometimes we forget how important our kidneys are until they begin to fail -- usually due to one or more of the following risk factors: high blood pressure, diabetes, heart disease, frequent UTIs, obesity, overuse of OTC/prescription drugs, an autoimmune disorder.

The good news is that there are a lot of simple things that we can do to protect our kidneys.

But, don't wait until you find out that you have protein leaking in your urine or that you have to go on kidney dialysis before you decide to do something about your kidneys!

Your Kidneys

Each of your kidneys is about 4 to 5 inches long and about 1 inch thick, weighing in at about 4.5 to 5 ounces. To put it into easy-to-visualize terms, each of your kidneys is a bit larger than a deck of cards. 

Although your kidneys make up less than 0.5 percent of your total body weight, they receive close to 25 percent of the total amount of blood that your heart pumps while you're resting. 

Also, your kidneys use up about 20 to 25 percent of your body’s supply of oxygen.

Although your kidneys are small organs (each about the size of a deck of cards), they receive so much of your blood and oxygen because they are responsible for five critical functions:

1. Your kidneys keep your blood clean by filtering it of waste products and eliminating these waste products from your body as urine.
2. Your kidneys help maintain a proper balance of fluids throughout your body.
3. Your kidneys secrete a hormone called erythropoietin, which is responsible for stimulating the production of red blood cells in your bone marrow.
4. Your kidneys produce an enzyme called renin, which is needed to help maintain your blood pressure.
5. Your kidneys convert vitamin D to its most active form.

How to Keep Your Kidneys Healthy

Recent studies indicate that 26 million American adults suffer from chronic kidney disease (CKD) and that the number is likely to rise unless Americans get serious about prevention. Primary risks include: diabetes; heart disease; high blood pressure; a family history of kidney failure; and age 60-plus. 

Secondary risks include: obesity; autoimmune diseases; urinary tract infections and systemic infections. Exercising regularly and controlling weight are just two of the ten ways keep your kidneys healthy.

Here are three important ways to protect your kidneys from prematurely breaking down:

1. Don't drink too much water.

Given the work that your kidneys are forced to undertake to filter your blood and produce urine, drinking large amounts of water when you’re not thirsty is a good recipe for prematurely wearing down your kidneys as you age. 

Your body is not like a plumbing tube that gets cleaner by flushing large amounts of water through it. A number of your organs, including your kidneys, are designed to keep your body clean by continuously eliminating waste materials. If you want to prevent illness as you age, a top priority should be to prevent unnecessary burden to your kidneys and other waste-eliminating organs.

2. Don’t eat too much protein, especially animal protein.

Eating more protein than you need leads to a greater workload on your kidneys, which must filter a by-product of protein metabolism called blood urea nitrogen (BUN) out of your blood. This increased workload can contribute to premature breakdown of the glomeruli in your kidneys.

If you have healthy kidneys, you can safely eat up to half of your body weight (in pounds) in grams per day. For example, if you weigh 150 pounds and are in good health, you can safely eat up to 75 grams* of protein (~ 10 oz.) from minimally processed foods per day. If you have problems with your kidneys, you should decrease this amount to a level that results in a healthy blood urea nitrogen level.

If your current health status is such that you need an objective way to monitor how well your body is responding to the amount of protein that you are eating, ask your doctor about monitoring your BUN level. Whenever you eat protein, your body breaks it down into amino acids that contain nitrogen. Nitrogen separates from amino acids and combines with other molecules to form urea. Urea is eliminated from your body when your kidneys filter it out of your blood and into your urine.

A healthy range for BUN is between 4 to 17 mg/dL. Anywhere between 18 to 21 mg/dL is a sign that you may be eating too much protein, and possibly that your kidneys are under excessive strain. More than 21 mg/dL is a strong sign that you need to significantly reduce your protein intake.

The link between eating too much protein and developing kidney disease is one that is not often talked about by supporters of a high-protein diet. While it is important to keep your blood sugar and insulin at healthy levels by avoiding sugar and other simple carbohydrates, please know that a high-protein diet may poses a danger to your health, especially if most of your protein is animal-based and is cooked at high temperatures. 

Your health is best served by eating mostly plant-based proteins, fats and carbohydrates. If you still prefer animal meat for your protein, eat primarily free-range, organic meats and avoid the antibiotics and growth hormones in most conventional meats.

*Note: There are about 7 g of protein in 1 ounce of cooked meat. So, for example, 4 ounces of raw boneless skinless chicken breast yields about 3 ounces of cooked chicken, or 21 g of protein. Most healthy adults need about 0.8 g of protein per kilogram of body weight. To calculate pounds, divide your weight by 2.2 to convert to kilograms and multiply by 0.8 to find the protein grams recommended for your weight each day. For example, a 175-pound person would need about 64 g of protein each day.

3. Don’t take prescription drugs and over-the-counter pain pills on a regular basis.

As many professional athletes have discovered during the past several years, regular use of prescription anti-inflammatory pain medication like Vioxx, Indocin, and Naprosyn poses even greater danger to kidney health than over-the-counter pain killers.

Non-steroidal anti-inflammatory drugs like ibuprofen (Advil, Motrin), naproxen (Aleve), and aspirin are known to cause kidney damage if taken regularly. Acetaminophen (Tylenol and Excedrin) can also cause kidney damage and failure if used regularly. All of these over-the-counter pain medications probably don’t pose significant danger if your kidneys are relatively healthy and you use them for emergencies only.

Here are additional ways to keep your kidneys healthy.

• Follow a healthful plant-based diet
• Don't smoke or abuse alcohol
• Don't overuse over-the-counter painkillers or NSAIDs
• Control weight
• Monitor blood pressure & cholesterol
• Exercise regularly
• Get an annual physical
• Know your family's medical history
• Learn about kidney disease
• Talk to your doctor about getting tested if you're at risk for CKD

Please remember that the best "medicine" for all of your organs, your kidneys included, is eating a plant-based, minimally processed diet, getting enough physical and emotional rest, getting regular exposure to fresh air and sunlight (without getting burned), and being physically active.

Note: For more details about maintaining and improving your kidney health, read Chapters 14 and 15 of the Death to Diabetes book (or ebook).