Dr. Sean Hashmi, a respected nephrologist and specialist in obesity medicine, revisits the science behind coffee and kidney health, expanding on the insights he first shared in his widely viewed 2020 video.
Drawing from the latest research, he explains that moderate coffee consumption—about two to three cups a day—appears not only safe for most individuals, including those with kidney concerns, but may also offer protective benefits for kidney function. Still, he emphasizes the importance of balance: coffee should be enjoyed in moderation, with careful attention to how it affects blood pressure, sleep quality, and anxiety. His message is clear—while coffee can be part of a healthy lifestyle, it should never come at the expense of rest or overall well-being, and any changes to one’s routine should be discussed with a healthcare provider.
Protective Sips: Coffee, Tea, and Matcha in Moderation
It’s no surprise that green tea and matcha, like coffee, can help protect kidney function. Yet their benefits come with nuances—certain cases require caution. In moderation, all three drinks show consistent protective effects thanks to their antioxidants: two to three cups daily for coffee or green tea, and one to two for matcha. The key is balance—stay hydrated, choose unsweetened versions, and seek a nephrologist’s guidance if you have kidney disease, stones, or take medications. Current evidence from large studies up to 2025 supports these findings.
|
Beverage |
Protective Benefits |
Warnings and Cautions |
|
Coffee |
- Moderate intake (2–3 cups/day) associated with 14–24% lower risk of chronic kidney disease (CKD), slower eGFR decline, reduced proteinuria, and lower CKD mortality. - ~20% lower risk of acute kidney injury (AKI). - Potential protection against kidney stones (via diuretic and antioxidant effects). - Mechanisms: Antioxidants (chlorogenic acids,
polyphenols), anti-fibrotic effects from caffeine, improved blood flow,
insulin sensitivity. |
- High doses may temporarily raise blood pressure (limit if uncontrolled hypertension). - Caffeine can disrupt sleep. - Avoid phosphate-rich additives (creamers, syrups). - In late-stage CKD (stages 4–5), limit to ~1 cup/day and monitor potassium. - Safe in moderation for most, including
early CKD; decaf retains many benefits. |
|
Green
Tea |
- Regular intake (2–4 cups/day) linked to lower CKD risk, higher eGFR, reduced albuminuria, and lower mortality in CKD patients. - Lower risk of acute kidney injury and kidney stones (especially in men; catechins may inhibit stone formation). - Strong antioxidant/anti-inflammatory effects from EGCG (reduces oxidative stress, fibrosis, inflammation in kidneys). - Potential benefits in
diabetic nephropathy and overall renoprotection. |
- Contains oxalates; excessive intake may increase kidney stone risk in susceptible individuals (though moderate amounts often protective). - Lower caffeine than coffee but avoid late-day if sleep-sensitive. - In late-stage CKD, avoid high doses (potential worsening in severe cases). -
Unsweetened is best, monitor if on potassium restrictions. |
|
Matcha |
- Higher concentration of EGCG and antioxidants than regular green tea → potentially stronger protection against CKD progression, oxidative stress, inflammation, and diabetic kidney damage. - May ameliorate renal/hepatic damage in models; supports overall kidney function via anti-fibrotic and antioxidant mechanisms. - Similar stone protection as green tea
(catechins may inhibit crystal formation). |
- Higher oxalates than brewed green tea (due to consuming whole leaf) → greater potential risk for kidney stones if excessive (limit to 1–2 servings/day if prone). - Avoid high doses in late-stage CKD or severe renal failure. - Moderate caffeine; monitor potassium in advanced CKD. - Moderation key (1–2 cups/day) for safety. |
References
- Kanbay M, et al. (2021). Effect of Coffee Consumption on Renal Outcome: A Systematic Review and Meta-Analysis of Clinical Studies. J Ren Nutr. PMID: 32958376. (Meta-analysis: Coffee linked to lower incident CKD, ESKD, and albuminuria.)
- Lew QJ, et al. (2020). Coffee Consumption is Associated with a Decreased Risk of Incident Chronic Kidney Disease: A Systematic Review and Meta-analysis of Cohort Studies. Eur J Intern Med. PMID: 32317238. (Decreased CKD risk with coffee.)
- Kennedy OJ, et al. (2022). Coffee Consumption May Mitigate the Risk for Acute Kidney Injury: Results From the Atherosclerosis Risk in Communities Study. Kidney Int Rep. PMID: 35812301. (Lower AKI risk with higher coffee intake.)
- Yuan S, et al. (2021). Coffee and Caffeine Consumption and Risk of Kidney Stones: A Mendelian Randomization Study. Am J Kidney Dis. PMID: 34690004. (Causal reduction in kidney stones.)
- Hu EA, et al. (2018). Coffee Consumption and Incident Kidney Disease: Results From the Atherosclerosis Risk in Communities (ARIC) Study. Am J Kidney Dis. PMID: 29571833. (Lower incident CKD risk.)
- Kanlaya R, Thongboonkerd V (2019). Protective Effects of Epigallocatechin-3-Gallate from Green Tea in Various Kidney Diseases. Adv Nutr. PMID: 30615092. (Review: EGCG protects against AKI, CKD, diabetic nephropathy, stones, fibrosis via antioxidation/anti-inflammation.)
- Shu L, et al. (2019). Green Tea Intake and Risk of Incident Kidney Stones: Prospective Cohort Studies in Middle-Aged and Elderly Chinese Individuals. Int Urol Nephrol. PMID: 30408844. (Lower stone risk, stronger in men.)
- Zhang Y, et al. (2023). Tea Consumption and New-Onset Acute Kidney Injury: The Effects of Milk or Sweeteners Addition and Caffeine/Coffee. Nutrients. PMID: 37432322. (Reversed J-shaped AKI risk; moderate tea protective.)
- Borgesi J, et al. (2022). Causal Association Between Tea Consumption and Kidney Function: A Mendelian Randomization Study. Front Nutr. PMID: 35425787. (Causal lower CKD risk and higher eGFR.)
- Yamabe N, et al. (2009). Matcha, a Powdered Green Tea, Ameliorates the Progression of Renal and Hepatic Damage in Type 2 Diabetic OLETF Rats. J Med Food. PMID: 19735169. (Matcha-specific: Reduces AGEs, oxidative stress in diabetic nephropathy model.)
- Kanlaya R, et al. (2016). Epigallocatechin-3-Gallate Attenuates CKD Progression via Anti-Apoptotic/Anti-Inflammatory Mechanisms. (Related to EGCG review.)
- Shehata et al. (2025). The Biological Effects of Matcha on Kidney Health. (Recent review emphasizing catechins' renoprotection.)

