The 'Healthy' Food That Could Be Damaging Your Kidneys Over 60, According to Nephrologists

There are areas of our bodies that we become particularly mindful of as we age-our hearts and bones, for example-but what about our kidneys? How are these organs impacted as the years progress?

According to Dr. Uday Nori, MBBS, Transplant Nephrologist at The Ohio State University Wexner Medical Center, kidney function begins naturally declining by about 1% after the age of 40, but it's faster with systemic diseases like high blood pressure and diabetes.

That's why it makes sense that those who are 60 years old or older are even more predisposed to declining kidney function.

"Adults over 60 are particularly vulnerable due to natural kidney aging," says nephrologist Dr. Stefanie Diaz, MD. "The kidneys have less reserve capacity in handling dietary stress."

As it turns out, some of that dietary stress is caused by seemingly healthy foods that all of us are encouraged to eat regularly. But it can surprisingly bring on kidney disease, which Dr. Nori calls "highly prevalent."

"It is estimated that about 30 million Americans have kidney disease today and only one out of nine people even know about it," he further says.

Related: Doctors Warn This ‘Normal' Pain Could Actually Be a Sign of Kidney Issues

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Why Is Food Damaging to Kidneys?

Since the kidneys act as the body's filtration system, a number of foods can damage the kidneys.

For instance, Dr. Tim Pflederer, MD FASN FASDIN, Chief Medical Director of Evergreen Nephrology, says that a diet high in red meats increases the work of filtration of the kidneys, leading to scarring within the filters and chronic kidney damage (CKD).

Dr. Pflederer adds that ultra-processed foods, such as sugar-sweetened beverages, fast foods, frozen meals, chips, candy and pastries, are high in salt, sugar and fat, which promote inflammation and may contribute to worsening CKD.

"Alternatively, a predominantly plant-based protein diet can reduce the risk or delay worsening of CKD," Dr. Pflederer says. "Processed meats also carry high sodium and phosphorus additive loads that contribute to hypertension and CKD-related bone disease."

But even certain foods that are core to a plant-based diet could eventually bring about kidney damage.

Related: The Common Habit That Could Be Damaging Your Kidneys, According to a Nephrologist

The ‘Healthy' Food That's Silently Damaging Your Kidneys Over 60, According to Nephrologists

"Spinach is high in oxalate, so for people who are predisposed to kidney stones, it can cause calcium oxalate kidney stones," Dr. Pflederer cautions. "If kidney stones block the ureter draining tubes, they not only cause pain but can cause damage to the kidneys."

He also says that there is some evidence that a very high oxalate diet (high in spinach content) can cause chronic kidney damage due to oxalate passing through the filters and causing inflammation in the kidneys.

"This is especially true for people over 60 because the aging kidney is more susceptible to damage from any cause," he says.

Dr. Diaz explains that spinach is "the most important dietary source of oxalate." "A metabolic study demonstrated that spinach was the only food tested that was capable of leading to high oxalate levels in the urine in normal subjects," she says.

Dr. Diaz says that oxalate is a naturally occurring compound in many plant foods. Dr. Nori also lists star fruit, rhubarb and chard as plant-based foods that can cause kidney damage if consumed in large quantities.

You don't necessarily need to swear off the green stuff, but you should be mindful of your spinach consumption if you have certain kidney-related health conditions.

"The risk depends on total oxalate intake, frequency and individual susceptibility," says Dr. Pflederer, referring to having a history of prior kidney stones.

Dr. Pflederer says that potentially harmful intake patterns of spinach include:

• Large, concentrated consumption (i.e. smoothies or juicing): less than two cups daily in liquid form can exceed 1,200 mg oxalate/day, "which may overwhelm renal excretion."
• Frequent high intake: eating spinach ≥8 times/month has been associated with increased kidney stone risk in some populations.

But the great nutritional benefits of spinach are to be considered as well.

"For most people, typical dietary intake does not cause kidney damage and indeed the health benefits outweigh the risks except for those with a tendency to kidney stones," Dr. Pflederer notes.

Related: The #1 Habit That Can Make Your Kidneys Healthier, According to a Nephrologist

Symptoms of Kidney Damage

Dr. Pflederer says that chronic kidney damage affects 37 million people in the United States, with about 9 in 10 unaware they have it "because the disease typically has no symptoms in its early stages."

Dr. Diaz says that people don't have symptoms until the later stages of chronic kidney disease, "and they tend to be nonspecific."

She lists these symptoms as fatigue, mild itching, and decreased appetite. "As kidney function gets worse, symptoms are more pronounced and can include foamy urine, swelling, nausea, weight loss, urine frequency and difficulty concentrating on tasks," Dr. Diaz says.

Up Next:

Sources

• Uday Nori, MBBS, Transplant Nephrologist at The Ohio State University Wexner Medical Center.
• Stefanie Diaz, MD, nephrologist.
• Dr. Tim Pflederer, MD FASN FASDIN, Chief Medical Director of Evergreen Nephrology.
• Urology: "Bioavailability of oxalate in foods"

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This story was originally published June 20, 2026 at 2:25 PM.