Is Olive Oil Good for Your Kidneys? What the Research Shows
Is olive oil good for your kidneys? The honest answer is that olive oil is a kidney-friendly fat, but not a kidney treatment. It contains almost no potassium, phosphorus, sodium or protein — the nutrients people with kidney disease are most often asked to watch — and it sits at the centre of the Mediterranean diet, which has been studied in people with chronic kidney disease (CKD). The human evidence on kidney function itself is limited and mixed: one randomised trial found no extra benefit over a low-fat diet, while a 2026 meta-analysis found a modest slowing of decline in mild-to-moderate CKD. This guide sets out what those studies measured, what they did not, and why anyone with CKD should agree diet changes with their renal team or dietitian.
For our own oil, see our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml). The research below applies to olive oil in general, ours included.
The Short Answer
- Olive oil is generally considered a kidney-friendly fat: USDA FoodData Central lists 1 mg potassium, 0 mg phosphorus, 2 mg sodium and no protein per 100 g.
- In the PREDIMED trial's Reus kidney sub-study (Díaz-López and colleagues, 2012), 665 older adults were followed for a year; kidney function improved similarly on a Mediterranean diet with virgin olive oil, with nuts, or on low-fat advice.
- A 2026 meta-analysis of 10 studies (1,073 adults with non-dialysis CKD) found the Mediterranean diet linked to a modest eGFR gain of 2.44 mL/min/1.73 m², with lower CRP where high-phenolic extra virgin olive oil was used.
- Most "olive oil protects the kidneys" claims online rest on animal studies, which cannot show what happens in people.
- If you have CKD or are on dialysis, potassium and phosphate limits come from other foods; agree any diet change with your renal team or dietitian.
- There is no evidence that an olive oil "flush" helps pass kidney stones; the NHS advice is water, with fresh lemon juice if you like, and urgent help for severe pain.
What Olive Oil Brings to a Kidney-Friendly Plate
Olive oil is almost pure fat. USDA FoodData Central (SR Legacy entry 171413) lists, per 100 g, 884 kcal, 1 mg potassium, 0 mg phosphorus, 2 mg sodium and 0 g protein. A 13.5 g tablespoon therefore adds roughly 119 calories and practically none of the minerals a renal diet usually restricts.
That is why kidney charities such as the US National Kidney Foundation list olive oil among the fats that suit a kidney-friendly diet: it adds flavour and energy without adding to a potassium, phosphate or salt allowance. It is a cooking choice, not an active ingredient — the benefit is in what it replaces (butter, ghee, processed spreads) and what it carries (vegetables, grains and pulses that fit your plan).
The one number worth watching is calories. Our olive oil calories guide gives per-teaspoon figures, and our guide to how much olive oil per day sets out the amounts the main studies actually used.
What the Human Studies Show
Four kinds of human research are worth knowing. They point in a broadly reassuring direction, but none shows that olive oil on its own protects or restores kidney function.
| Study | Who and how many | What was compared | Kidney finding |
|---|---|---|---|
| Díaz-López et al., 2012 (PREDIMED, Reus) | 665 adults aged 55–80 at high cardiovascular risk, 1 year | Mediterranean diet + virgin olive oil vs + nuts vs low-fat advice | eGFR rose in all three groups, by similar amounts; no extra benefit from the Mediterranean diets |
| Zhou et al., 2026 (meta-analysis) | 10 studies, 1,073 adults with non-dialysis CKD | Mediterranean diet vs control diets | eGFR +2.44 mL/min/1.73 m², high heterogeneity; CRP lower with high-phenolic EVOO |
| García-González et al., 2026 (OLTRAD) | 97 adults with type 2 diabetes, 12 months | Oleanolic-acid-enriched olive oil vs standard olive oil | Slower eGFR decline with the enriched oil, only in those with mildly reduced eGFR; exploratory |
| Marrone et al., 2022 | 40 CKD patients, 9 weeks, no control group | 40 mL/day of high-polyphenol EVOO | Lower inflammation and oxidative-stress markers; a cardiovascular, not kidney-function, study |
PREDIMED: a fair test, and a null result
Díaz-López and colleagues (2012, American Journal of Kidney Diseases) measured estimated glomerular filtration rate (eGFR) and urine albumin in a PREDIMED cohort from Reus, Spain. After one year, eGFR rose by 4.7, 3.5 and 4.1 mL/min/1.73 m² in the olive oil, nuts and low-fat groups respectively. The authors concluded the results did not support a kidney benefit from the Mediterranean diet over and above low-fat advice.
The 2026 meta-analysis: modest, and mostly in mild-to-moderate CKD
Zhou and colleagues (2026, Frontiers in Nutrition) pooled 10 interventional and observational studies. The Mediterranean diet was associated with an eGFR difference of 2.44 mL/min/1.73 m² (95% CI 0.16 to 4.72), but heterogeneity was very high (I² = 90%), and the benefit looked more consistent where eGFR was 45 or above. A drop in C-reactive protein was linked specifically to high-phenolic extra virgin olive oil, and the diet did not adversely affect serum potassium or phosphorus.
The OLTRAD trial adds a caution of its own: its "olive oil" was an experimental oil enriched with oleanolic acid, and the authors describe the kidney analysis as hypothesis-generating. It tells us something about that compound, not about a bottle from a shop shelf.
Why Olive Oil Comes Up in Kidney Research at All
The NHS lists high blood pressure, diabetes and high cholesterol among the main causes of CKD. Olive oil has been studied for each of those, which is the main reason it keeps appearing in kidney research: if a dietary pattern helps the conditions that strain the kidneys, the kidneys might benefit indirectly. Our guides to olive oil and blood pressure and olive oil and diabetes cover that research.
The second reason is polyphenols. Extra virgin olive oil carries compounds such as hydroxytyrosol and oleocanthal, which have been studied for their effects on inflammation and oxidative stress — see our guide to olive oil polyphenols. Much of the direct "olive oil protects the kidney" research, though, is in rats and mice whose kidneys were damaged on purpose with drugs, toxins or induced diabetes. Animal work is a reason to keep studying, not evidence that olive oil does the same in people.
Olive Oil If You Have CKD or Are on Dialysis
If you have CKD, your renal team may have given you limits on potassium, phosphate, salt, protein or fluid. Olive oil does not interfere with those limits: with essentially no potassium or phosphorus, it is not the food a renal dietitian is usually worried about. That is also why it is the wrong place to look for help — potassium and phosphate are managed through other foods, medicines and dialysis, not by adding oil.
The NHS explains that people with CKD can develop high potassium levels and, when the kidneys are severely damaged, a build-up of phosphate. Those are the reasons your plan matters more than any single ingredient. A renal dietitian can show you how olive oil fits it — for example, as a way to add flavour to lower-potassium vegetables, or to add energy if you have been advised to keep your weight up.
One small dialysis trial is worth mentioning because it used olive oil directly. Ramos and colleagues (2015, Journal of Renal Nutrition) randomised 50 constipated haemodialysis patients to olive oil, flaxseed oil or mineral oil, starting at 4 mL a day, for four weeks, and found olive oil as effective as mineral oil for constipation. That is a gut finding, not a kidney one; our guide to olive oil for constipation covers it in context. Do not start it without asking your unit.
Kidney Stones: Why We Do Not Endorse an Olive Oil "Flush"
"Olive oil and lemon juice to pass kidney stones" is a popular home remedy. We could find no clinical trial testing olive oil, or an olive oil and lemon mix, for passing or preventing kidney stones. The lemon part has some standing: the NHS kidney stones page suggests adding fresh lemon juice to water, alongside drinking 2.5 to 3 litres of water a day as an adult and keeping salt down. The olive oil part has none.
The bigger risk is delay. The NHS advises asking for an urgent GP appointment or contacting NHS 111 if you think you have kidney stones and are in severe pain or have a high temperature or shivers, and says not to make changes to your diet without speaking to your doctor. A spoonful of oil cannot shift a stone; a stone with infection behind it needs treatment. Our article on olive oil, lemon and honey looks at what that kind of mix does and does not do.
The Honest Limits
"Kidney charities call olive oil kidney-friendly. Isn't that the same as good for the kidneys?"
Not quite. "Kidney-friendly" means it fits a renal diet without adding potassium, phosphate or salt. "Good for the kidneys" implies it improves kidney function, and the best trial evidence, from PREDIMED, did not find that over low-fat advice.
"The meta-analysis was positive, though."
It was, modestly. But it pooled 10 very different studies, many observational, with high heterogeneity, and it tested a whole dietary pattern rather than olive oil alone. It is encouraging, not proof.
"Does a better olive oil make a difference?"
Possibly for inflammation markers: the CRP finding in the 2026 meta-analysis was tied to high-phenolic extra virgin olive oil. For potassium and phosphate, no — every olive oil is essentially free of both. Our guide to choosing a quality olive oil explains how to tell extra virgin from refined.
Why Sidr & Stone
This article's argument is that olive oil earns its place in a kidney-friendly diet as a good food, not as a remedy. Sidr & Stone's Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml) is sold on those terms: an extra virgin kitchen oil, described plainly.
- Single-estate — Sidr & Stone's olive oil comes from our own family-owned farm near Marrakech, Morocco, and we control every step from tree to bottle, with no blending across origins.
- Rain-fed — our trees are not irrigated; they take what the season gives.
- Organically grown — no synthetic fertilisers, pesticides or herbicides are used (not yet certified; certification is in progress).
- Single harvest — a small, limited batch, picked when the fruit is ready; the current batch's details are on the product page.
- Cold-pressed within hours of harvest — mechanical extraction only, with no solvents, no refining and no deodorising.
- Unfiltered extra virgin — minimally processed, so it may show natural sediment, which is normal.
- 100% natural — a single ingredient, olive oil, with nothing added.
- Dark glass with a gold label — protective packaging against light.
- 10% of profits to charity — a brand-wide commitment.
- Fulfilment in the UK, EU, and US.
We will not tell you our oil is good for your kidneys — no olive oil can honestly promise that. What we will say is that it is single-estate Moroccan, rain-fed, organically grown and cold-pressed within hours of harvest, and that it belongs in your kitchen, inside whatever plan your renal team has agreed with you.
Frequently Asked Questions
Is olive oil good for your kidneys?
Olive oil is a kidney-friendly fat because it contains almost no potassium, phosphorus, sodium or protein. Human studies have not shown that it improves kidney function on its own; the evidence is for the Mediterranean diet as a whole, and it is mixed.
Can olive oil reduce creatinine?
There is no good evidence that olive oil lowers creatinine. Trials measured eGFR, which is calculated from creatinine, and the PREDIMED kidney sub-study found similar changes with or without olive oil. Ask your renal team about any change in your results.
How much olive oil can a kidney patient have?
There is no kidney-specific limit, because olive oil adds almost no potassium or phosphate; the practical limit is calories, about 119 per tablespoon. Your renal dietitian can set an amount that suits your weight and plan.
Is extra virgin olive oil better for the kidneys than regular olive oil?
For potassium and phosphate, there is no difference. The 2026 meta-analysis linked lower inflammation markers specifically to high-phenolic extra virgin olive oil, which is a reason to prefer extra virgin, not proof of a kidney benefit.
Is Sidr & Stone olive oil suitable for a kidney diet?
Like any extra virgin olive oil, ours is a single-ingredient oil with essentially no potassium, phosphorus or salt. Whether and how much to use is a question for your renal team or dietitian.
Does olive oil and lemon juice help pass kidney stones?
No trial has tested it. The NHS suggests plenty of water, fresh lemon juice in water if you like, and urgent medical help for severe pain or a high temperature.
Where can I buy Sidr & Stone olive oil?
Our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml) is available to pre-order from the product page as a limited single-harvest batch, with fulfilment in the UK, EU, and US.
Is olive oil a medicine?
No. Olive oil is a food, not a medicine. It has a long traditional history — including being honoured in the Prophetic Sunnah — and a substantial body of modern research, particularly around polyphenols, cardiovascular health, and the Mediterranean diet pattern. It can be a worthwhile part of a healthy routine, but it does not cure diseases and is not a substitute for medical care. Be cautious of any olive oil marketed with specific disease-cure claims.
Final Thoughts
Olive oil is a good fat for a kidney-friendly diet for a simple reason: it brings flavour and energy without the potassium, phosphate and salt that kidney diets restrict. What it has not shown, in people, is that it protects or restores kidney function on its own. The best trial found no extra benefit over low-fat advice; the most recent meta-analysis found a modest one for the Mediterranean diet as a whole.
If you have CKD or are on dialysis, use it as part of the plan your renal team or dietitian has agreed, not instead of it. If you think you have a kidney stone, drink water and get medical advice — leave the flush alone.
Our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml) — single-estate, rain-fed and cold-pressed within hours of harvest — is available to pre-order now as a limited single-harvest batch, with fulfilment in the UK, EU, and US.
Our extra virgin olive oil is grown organically on our own single-estate farm on the plains outside Marrakech: we control every step from tree to bottle, and no synthetic pesticides, herbicides or fertilisers are used. It is not yet certified organic — certification is in progress, and we will publish it as soon as it comes through.
References
- Díaz-López A, Bulló M, Martínez-González MÁ, Guasch-Ferré M, Ros E, Basora J, Covas MI, del Carmen López-Sabater M, Salas-Salvadó J; PREDIMED (Prevención con Dieta Mediterránea) Reus Study Investigators. Effects of Mediterranean diets on kidney function: a report from the PREDIMED trial. Am J Kidney Dis. 2012;60(3):380-389. doi:10.1053/j.ajkd.2012.02.334. PMID: 22541738.
- Zhou C, Li Y, Huang M, Bai M, Xing Y. Mediterranean diet with high-phenolic EVOO slows kidney function decline and reduces inflammation in nondialysis CKD: a meta-analysis. Front Nutr. 2026;13:1792390. doi:10.3389/fnut.2026.1792390. PMID: 41847236.
- García-González A, Matamoros-Domínguez A, Espinosa-Cabello JM, Pérez-Muñoz G, Aranda MJL, Roque-Cuellar MDC, García-Rey S, Jiménez-Sánchez A, Martínez-Ortega AJ, Mangas-Cruz MÁ, Cerrillo I, Perona JS, García-Luna PP, Yubero-Serrano EM, Castellano JM. Oleanolic Acid-Enriched Olive Oil Attenuates Kidney Function Decline in Patients With Type 2 Diabetes: Results From the OLTRAD Randomised Controlled Trial. Diabetes Obes Metab. 2026. doi:10.1111/dom.71206. PMID: 42608317.
- Marrone G, Urciuoli S, Di Lauro M, Ruzzolini J, Ieri F, Vignolini P, Di Daniele F, Guerriero C, Nediani C, Di Daniele N, Noce A. Extra Virgin Olive Oil and Cardiovascular Protection in Chronic Kidney Disease. Nutrients. 2022;14(20):4265. doi:10.3390/nu14204265. PMID: 36296948.
- Ramos CI, Andrade de Lima AF, Grilli DG, Cuppari L. The short-term effects of olive oil and flaxseed oil for the treatment of constipation in hemodialysis patients. J Ren Nutr. 2015;25(1):50-56. doi:10.1053/j.jrn.2014.07.009. PMID: 25238699.
- US Department of Agriculture, Agricultural Research Service. FoodData Central: Oil, olive, salad or cooking (SR Legacy, FDC ID 171413). Accessed 2 October 2026. https://fdc.nal.usda.gov/food-details/171413/nutrients
- NHS. Chronic kidney disease; Chronic kidney disease – Treatment; Kidney stones. Accessed 2 October 2026. https://www.nhs.uk/
Disclaimer: This article summarises published research and NHS guidance on olive oil and kidney health at the time of writing; research findings and guidance may change, and readers should check current sources. It is general information, not personal medical advice, and does not replace advice from your GP, renal team or dietitian — if you have kidney disease or are on dialysis, agree any change to your diet with them first. Olive oil is a food, not a medicine, and is not a substitute for medical treatment of any condition. For any health concern, consult a qualified medical professional.