Why eating spinach might give you kidney stones
Dietary influences on urinary oxalate and risk of kidney stones.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Dietary oxalate contributes 40–50% of urinary oxalate—even in healthy people eating normal diets.
Most people assume kidney stones are caused by too much calcium or salt. This shows oxalate from plants is a bigger driver than most realize, and it’s unavoidable if you eat vegetables.
Practical Takeaways
If you’ve had kidney stones, ask your doctor for a 24-hour urine test to check if you’re a hyperabsorber—then tailor your diet accordingly.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Dietary oxalate contributes 40–50% of urinary oxalate—even in healthy people eating normal diets.
Most people assume kidney stones are caused by too much calcium or salt. This shows oxalate from plants is a bigger driver than most realize, and it’s unavoidable if you eat vegetables.
Practical Takeaways
If you’ve had kidney stones, ask your doctor for a 24-hour urine test to check if you’re a hyperabsorber—then tailor your diet accordingly.
Publication
Journal
Frontiers in bioscience : a journal and virtual library
Year
2003
Authors
L. Massey
Related Content
Claims (5)
If you eat a normal diet with about 150 to 250 milligrams of oxalate a day, roughly half of the oxalate that shows up in your urine comes from the food you eat—so what you eat really matters for how much oxalate your body gets rid of.
Some people who get kidney stones absorb way more oxalate from their food than people who don’t get stones, and that extra oxalate ends up in their urine, which can help form stones.
Kidney stones are often made of calcium oxalate, and even small increases in oxalate in your urine can make stones more likely to form—much more than similar increases in calcium—because your body naturally has way less oxalate to begin with.
When people who don’t get kidney stones eat foods with oxalate, their bodies only absorb a tiny bit—about 3 to 8%—and most of it just passes through and comes out in poop.
Different types of the same vegetable or fruit can have wildly different amounts of oxalate—sometimes 2 to 15 times more—because of how they’re grown or what kind they are, making it hard to give simple diet advice.