If you've been thinking about kidney health and your glomerular filtration rate (GFR), you may be wondering if diet can improve it. According to experts, what you do and don't eat can affect your GFR and kidneys. Here's a breakdown of how diet plays a role in GFR health.
Your GFR is the best overall indicator of kidney function, according to the National Kidney Foundation (NKF).
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"We each have two kidneys, and, in a healthy state, each has about 800,000 filtering units called nephrons," says Chicago-based Holly Kramer, MD, MPH, professor of public health sciences at Loyola University and spokesperson for the NKF.
Your total GFR is the sum of filtration of each one of these filters. In most healthy people, a normal GFR is 90 mL/min/1.73 m2 or higher, per the NKF.
This is a lot of nephrons, and we don't always need all of them, which is why healthy people can donate a kidney and still have normal kidney function, Dr. Kramer says.
Your doctor can estimate your GFR with a blood test measuring your creatinine level and some other factors such as sex, age, weight and race, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Improving GFR With Diet
In people with kidney disease, high blood pressure or poorly controlled diabetes, nephrons can become scarred, Dr. Kramer says.
"To compensate, they work harder, which causes more scarring," she says. While what's done is done, eating a healthy diet can help prevent further GFR decline and scarring of nephrons, according to the NKF.
Here are four strategies that might help.
1. Limit Processed Meats
One way to mitigate further GFR decline is by limiting processed meats from your diet, Dr. Kramer says, such as:
- Hot dogs
- Cured bacon
"These are high in sodium and preservatives, so you retain fluids, and that adds extra work for your kidneys," she says.
2. Cut Back on Red Meat
Another food Dr. Kramer suggests limiting for GFR health is red meat and other animal proteins, as these are high in sulfur amino acids that must be excreted by your kidneys.
"It's a lot more work for the kidney to get rid of these extra acids," Dr. Kramer says. "This stimulates hormones in your kidney that lead to increased sodium retention, higher blood pressure and more scarring of nephrons."
If you do eat meat, choose chicken and fish — and make sure your portion is no bigger than the size of your palm, she says.
"Eating too much protein can cause waste to build up in your blood, and your kidneys may not be able to remove all the extra waste," Dr. Kramer says.
3. Eat More Fresh Produce
Eating more veggies and fruit will help prevent and slow the progression of chronic kidney disease, type 2 diabetes, high blood pressure and heart disease, Dr. Kramer says.
You can dip your feet into a plant-based lifestyle by giving meatless Mondays a try, meaning you commit to no meat every Monday.
Research suggests that a plant-based diet is beneficial if you have early kidney disease and can help keep your kidneys from getting worse, according to the NKF.
4. Go Mediterranean
As far as diet plans go, there are many to choose from, Dr. Kramer says.
According to the NKF, the kidney-friendly Dietary Approaches to Stop Hypertension (DASH) diet is low in salt and rich in fruits, vegetables, low-fat dairy foods, whole grains, fish, poultry, beans, seeds and nuts.
Noting that everyone has different tastes and preferences, Dr. Kramer says another option is the Mediterranean diet, which "is high in olive oil, nuts, fresh fruit and vegetables, low in red meat and high in fish."
She suggests medical nutritional therapy, in which "a dietitian takes your history and comes up with an eating plan to help you manage disease," noting that the cost of this is covered by Medicare and many private insurers.
Ultimately, tweaking your diet is a win-win, Dr. Kramer says. "In addition to helping improve GFR rate, a healthier diet can also improve diseases that occur with, cause or worsen kidney function — such as high blood pressure — and lengthen your lifespan."
- National Kidney Foundation: “Frequently Asked Questions About GFR Estimates”
- National Institute of Diabetes and Digestive and Kidney Diseases:” Glomerular Filtration Rate (GFR)”
- National Kidney Foundation: “What Is a Plant-Based Diet, and Is It Good for Your Kidneys?”
- National Kidney Foundation: “The DASH Diet”
- National Kidney Foundation: “Can My GFR Get Better?”
- Holly Kramer, MD, MPH, double board-certified nephrologist; professor, public health sciences, Division of Nephrology and Hypertension, Loyola University; spokesperson, National Kidney Foundation; Chicago, Illinois
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