Does too much protein spoil my kidneys?

1. What You Hear
  • Eating a lot of protein always damages healthy kidneys.
  • High protein diets cause kidney disease in everyone.
  • Protein intake should be severely restricted to protect kidney health.
  • Animal protein is always bad for your kidneys.
  • If you have any kidney issues, all protein is harmful.
2. What The Science Says
For Healthy Individuals
  • Most recent meta-analyses find no significant kidney damage from high protein intake in healthy people.
  • Short- or long-term studies show normal kidney function is maintained despite increased protein.
  • Kidney hyperfiltration can occur as a normal adaptive response but does not cause long-term harm in healthy kidneys.

For Those with Pre-existing Kidney Conditions
  • Higher protein intake is linked to faster progression of chronic kidney disease (CKD).
  • Studies show high protein can increase glomerular hyperfiltration, leading to kidney injury in CKD.
  • Protein intake should be moderated (about 0.55–0.8 g/kg/day) to slow CKD progression.
  • Some studies suggest plant protein might be less harmful than animal protein in CKD.
3. What Actually Causes Kidney Damage
  • Diabetes and high blood pressure are the leading causes of kidney damage worldwide.
  • Chronic inflammation and autoimmune conditions (like lupus) can damage kidneys.
  • Prolonged use of some medications (NSAIDs, some antibiotics) may harm kidney function.
  • Untreated infections, kidney stones, or obstructions can cause kidney injury.
  • Severe dehydration and toxins (heavy metals, drugs) also contribute to kidney damage.
  • Lifestyle factors such as smoking and excessive alcohol consumption worsen kidney health.
  • Excessive protein intake alone does not cause kidney damage in healthy individuals but may strain kidneys if combined with other risk factors.
4. What This Means For You For Healthy Individuals
  • Enjoy a balanced protein intake appropriate for your activity (generally 1–1.5 g/kg/day).
  • No need to fear moderate or high protein from varied sources.
  • Maintain overall healthy lifestyle: balanced diet, exercise, hydration.

For Those with Pre-existing Kidney Conditions
  • Consult with healthcare providers to moderate protein intake (generally 0.55–0.8 g/kg/day).
  • Prefer plant-based protein sources when possible.
  • Monitor kidney function regularly.
  • Avoid excess sodium, manage blood pressure, and follow personalized nutritional advice.
5. Where Everything You Read Above Came From
  • Cheng Y, Zheng G, et al. Association between dietary protein intake and risk of chronic kidney disease: a systematic review and meta-analysis. Front Nutr. 2024 Jun 14; DOI:10.3389/fnut.2024.1408424. https://www.frontiersin.org/articles/10.3389/fnut.2024.1408424/full
  • Ko GJ, Obi Y, Tortorici AR, Kalantar-Zadeh K. The Effects of High-Protein Diets on Kidney Health and Longevity. J Am Soc Nephrol. 2020 Jul 15; DOI:10.1681/ASN.2019070694. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460905/
  • Lambert K, et al. Commentary on the 2020 update of the KDOQI clinical practice guideline for nutrition in CKD. Nutrients. 2022 Feb 3; DOI:10.3390/nu14030650. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9303594/
  • Carballo-Casla A, et al. Protein Intake and Mortality in Older Adults With CKD. JAMA Netw Open. 2024 Aug 1;7(8):e2419380. DOI:10.1001/jamanetworkopen.2024.19380. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10483290/
  • Martin WF, Armstrong LE, Rodriguez NR. Dietary protein intake and renal function. Nutr Metab (Lond). 2005 Sep 20;2:25. DOI:10.1186/1743-7075-2-25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1262767/
  • Kazancioğlu R. Risk factors for chronic kidney disease: an update. Kidney Int Suppl. 2013 Nov;3(4):368-371. DOI:10.1038/kisup.2013.77. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4089662/
  • Stremke ER, et al. Dietary protein intake and bone across stages of chronic kidney disease. Adv Nutr. 2020 Sep 1;11(5):1030-1041. DOI:10.1093/advances/nmaa038. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7255938/