Olive Oil and Diabetes: What the Research Shows About Blood Sugar
Olive oil and diabetes is one of the more searched pairings in nutrition, and for good reason: if you live with type 2 diabetes or prediabetes, or you are trying to stay clear of both, every fat on your plate starts to feel like a decision. The research here is genuinely better than for most foods. A Spanish randomised trial, a 2017 meta-analysis of cohort studies and trials, and a 2025 dose-response meta-analysis all point in the same direction. But they point at something more modest than the headlines — olive oil as the fat you choose instead of others, inside an overall eating pattern, not a spoonful that lowers blood sugar on its own. This article sets out what was actually measured, in whom, and where the evidence stops.
For our own oil, see our Cold-Pressed Single-Estate Extra Virgin Olive Oil — Marrakech.
The Short Answer
- Olive oil is a food, not a diabetes treatment. It does not lower blood sugar the way medication does, and it should never replace anything your GP or diabetes team has prescribed.
- In the PREDIMED trial (Salas-Salvadó et al., Annals of Internal Medicine, 2014), 3,541 older Spanish adults without diabetes who followed a Mediterranean diet supplemented with extra virgin olive oil developed type 2 diabetes at a lower rate than a low-fat control group over a median of 4.1 years.
- A 2017 meta-analysis by Schwingshackl and colleagues in Nutrition & Diabetes linked the highest olive oil intakes with a 16% lower risk of type 2 diabetes, and found small improvements in HbA1c (−0.27 percentage points) in people who already had it.
- Small meal studies suggest a little extra virgin olive oil added to a meal can soften the post-meal rise in blood glucose — including in 30 people with impaired fasting glucose.
- Most of the benefit appears to come from what olive oil replaces — butter, margarine, mayonnaise — not from adding extra calories on top of a normal diet.
- If you have diabetes, talk to your GP or diabetes team before making significant changes to your diet, and never adjust medication on the strength of a food.
Does Olive Oil Lower Blood Sugar?
Not directly, and not on its own. Pure olive oil contains no carbohydrate, so it does not raise blood glucose and has no glycaemic index in the usual sense. What research has measured is subtler: when extra virgin olive oil is part of a meal, or part of a long-term eating pattern, blood glucose responses and diabetes risk tend to look somewhat better than with other fats.
That distinction matters, because a great deal of online advice blurs it. A food that does not spike your blood sugar is not the same as a food that brings blood sugar down. Olive oil sits firmly in the first group. Any effect on glucose control comes through the meal and the diet around it — slower digestion of the carbohydrate it accompanies, a better fat profile than the fats it displaces, and the polyphenols present in genuine extra virgin oil.
It is also worth knowing where olive oil stands with regulators. The register of authorised nutrition and health claims that applies in Great Britain (assimilated Regulation (EU) No 432/2012, on legislation.gov.uk) lists one claim specific to olive oil — that olive oil polyphenols contribute to the protection of blood lipids from oxidative stress. No olive oil claim on that register concerns blood sugar. That is not proof of no effect; it is a reminder of how high the bar sits for a formal claim.
What the Research Measured: Prevention, Management and Single Meals
The olive oil and diabetes literature splits into three distinct questions, and they are often confused. The table below keeps them apart.
| Study | Design | Who | What it found | Main limit |
|---|---|---|---|---|
| Salas-Salvadó et al., Annals of Internal Medicine, 2014 (PREDIMED) | Subgroup analysis of a randomised trial | 3,541 adults aged 55–80 without diabetes, at high cardiovascular risk | Mediterranean diet with extra virgin olive oil: hazard ratio 0.60 for new type 2 diabetes vs low-fat control | Diabetes was a secondary outcome; randomisation not stratified by diabetes status |
| Guasch-Ferré et al., American Journal of Clinical Nutrition, 2015 | Two prospective cohorts | About 145,000 US women in the Nurses' Health Studies | More than 1 tablespoon a day vs never: hazard ratio 0.90 | Observational — association, not proof of cause |
| Schwingshackl et al., Nutrition & Diabetes, 2017 | Meta-analysis of 4 cohorts and 29 trials | People with and without type 2 diabetes | 16% lower risk at highest intake; HbA1c −0.27 percentage points in type 2 diabetes | Mixed study designs; effect sizes small |
| Du and Zhou, Journal of Health, Population and Nutrition, 2025 | Dose-response meta-analysis of 4 cohorts and 6 trials | Over 500,000 participants | 13% lower diabetes risk with olive oil consumption | Pools heterogeneous studies; associations, not mechanisms |
| Carnevale et al., Clinical Nutrition, 2017 | Randomised crossover meal study | 30 people with impaired fasting glucose | A meal with 10 g extra virgin olive oil lowered post-meal glucose vs the same meal without it | Single meals; very small sample |
Prevention: who develops type 2 diabetes
The strongest single piece of evidence is the PREDIMED diabetes analysis. Over a median follow-up of 4.1 years, there were 80 new cases of diabetes in the extra virgin olive oil group, 92 in the nut group and 101 in the control group — rates of 16.0, 18.7 and 23.6 per 1,000 person-years. Notably, the diets were not calorie-restricted and there was no exercise intervention. The authors were candid about weaknesses: diabetes was a prespecified secondary outcome, randomisation was not stratified by diabetes status, and more people withdrew from the control group.
The wider PREDIMED trial also had its original 2013 cardiovascular paper retracted and republished in 2018 over randomisation irregularities at some sites — we cover that history in our article on olive oil and heart health. The diabetes subgroup should be read with that in mind: encouraging, not settled.
Management: blood sugar in people who already have diabetes
For people already living with type 2 diabetes, the evidence is thinner. The Schwingshackl meta-analysis found that olive oil interventions reduced HbA1c by 0.27 percentage points and fasting glucose by 0.44 mmol/L more than control diets. Those are real but small numbers — useful as part of an overall diet, nowhere near the effect of prescribed treatment.
Single meals: the post-meal glucose rise
Meal studies by Violi, Carnevale and colleagues found that adding 10 g of extra virgin olive oil to a Mediterranean-type meal was associated with lower post-meal glucose in 25 healthy adults (Nutrition & Diabetes, 2015), and then in 30 people with impaired fasting glucose (Carnevale et al., 2017). These are short, small studies that measure a single meal, but they help explain why the fat you pair with carbohydrate can matter.
It Is Mostly About What Olive Oil Replaces
The most practical finding in this research is easy to miss. In the Nurses' Health Studies, Guasch-Ferré and colleagues estimated that substituting 8 g a day of olive oil for stick margarine, butter or mayonnaise was associated with a 5%, 8% and 15% lower risk of type 2 diabetes respectively. The benefit attaches to the swap.
That matches mainstream advice. Diabetes UK recommends cooking with small amounts of unsaturated oils such as rapeseed, sunflower or olive oil instead of butter, ghee, lard or coconut oil. Olive oil is not singled out as uniquely protective; it is one of the better fats to use in place of saturated ones.
There is a reasonable objection here, and it deserves a straight answer: fat is calorie-dense, and weight is central to type 2 diabetes. A tablespoon of any oil carries roughly 120 calories. Adding several spoonfuls of olive oil to an unchanged diet is not what the trials tested and could work against you. Use it to replace other fats, in the amounts you would normally cook with.
Why Extra Virgin Olive Oil Is the One Studied
PREDIMED supplied extra virgin olive oil specifically, and the Violi and Carnevale meal studies used it too. Part of the interest is the fat itself — olive oil is predominantly oleic acid, a monounsaturated fat — but part is the polyphenols, such as hydroxytyrosol, oleuropein and oleocanthal, which are largely removed when oil is refined. We explain these compounds in our guide to olive oil polyphenols.
So the grade on the label matters. "Light" or "pure" olive oil is refined and is not the product most of these studies used. Polyphenols also fade with heat, light and age, which is why freshness, dark glass and a clear origin are worth looking for. Our guide to choosing a quality olive oil covers the label checks, and our explainer on what extra virgin olive oil is covers the grading itself.
One honest caveat: the evidence does not show that a high-polyphenol oil produces better blood sugar results than an ordinary extra virgin oil in people. That is a reasonable hypothesis, not a demonstrated outcome.
How to Use Olive Oil Sensibly With Diabetes or Prediabetes
- Use it as your main cooking and dressing fat in place of butter, margarine, ghee or creamy dressings — not as an extra.
- Keep portions to what you would normally use; the 2025 meta-analysis pointed to roughly 10–20 g a day, about one to one-and-a-half tablespoons.
- Pair it with vegetables, pulses and whole grains, which is how it was eaten in the trials.
- Choose extra virgin, in dark glass, from a source that tells you its origin and harvest.
- Ignore "olive oil shots" or bedtime spoonfuls sold as blood-sugar fixes; no trial supports them.
- Discuss significant diet changes with your GP or diabetes team, especially if you take insulin or medicines that can cause low blood sugar.
- Never reduce or stop diabetes medication because of a food you have read about.
Why Sidr & Stone
The research on olive oil and diabetes is about extra virgin olive oil eaten as part of a sensible diet — so the honest thing we can offer is an oil made to be genuinely extra virgin, and transparency about how it is made. Sidr & Stone's Cold-Pressed Single-Estate Extra Virgin Olive Oil comes from our own family-owned farm on the plains outside Marrakech, Morocco.
- Single-estate — Sidr & Stone's olive oil comes from one family-owned farm near Marrakech; we control every step from tree to bottle, with no blending across origins.
- Rain-fed — the trees are not irrigated; they take what the season gives.
- Organically grown — no synthetic fertilisers, pesticides or herbicides are used (not yet certified organic; certification is in progress).
- Single harvest — a small, limited batch; once it is gone, it is gone until the next harvest.
- Cold-pressed within hours of harvest — to preserve flavour, aroma and polyphenols.
- Unfiltered extra virgin — minimally processed; natural sediment is normal.
- 100% natural — one ingredient, olive oil, nothing added.
- 500ml dark glass with a gold label — protection against the light that degrades polyphenols.
- 10% of profits to charity, with fulfilment in the UK, EU, and US.
We will not tell you our oil helps with diabetes — no olive oil can honestly claim that, and this article has explained why. 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 is the kind of extra virgin oil the research actually studied.
Frequently Asked Questions
Is olive oil good for diabetes?
Olive oil is one of the better fats for people with or at risk of type 2 diabetes when it replaces butter, margarine or other saturated fats. Trials and meta-analyses link it with lower diabetes risk and small improvements in blood sugar markers, but it is a food, not a treatment. Speak to your GP or diabetes team about your own diet.
Why might olive oil affect blood sugar at all?
Olive oil contains no carbohydrate, so it does not raise blood glucose itself. Fat slows the digestion of carbohydrate eaten with it, and meal studies suggest extra virgin olive oil may soften the post-meal glucose rise. Its monounsaturated fat and polyphenols are the most-studied reasons, but the mechanisms are not fully established.
How much olive oil can a diabetic have a day?
There is no official dose. The studies typically involved around 10–20 g a day — roughly one to one-and-a-half tablespoons — used in place of other fats. Because oil is calorie-dense, the amount that suits you depends on your overall diet and weight goals, which your GP, dietitian or diabetes team can help with.
Does olive oil have a glycaemic index?
No. The glycaemic index measures how carbohydrate-containing foods raise blood glucose, and pure olive oil contains no carbohydrate. That is why you will see it described as having a GI of zero or "not applicable". What matters more is the meal it is part of.
How does Sidr & Stone's oil compare with supermarket olive oil?
Ours is single-estate, rain-fed, organically grown (not yet certified) and cold-pressed within hours of harvest, sold in dark glass. Many supermarket oils are blends, and "light" or "pure" olive oils are refined. Whatever you buy, choose extra virgin — it is the grade the diabetes research used.
Can olive oil replace metformin or other diabetes medication?
No. Nothing in this article should be read that way. Olive oil is a food that can be part of a healthy diet; it is not a substitute for any prescribed medicine. Never stop or reduce diabetes medication without speaking to your GP or diabetes team.
Where can I buy cold-pressed extra virgin olive oil?
Sidr & Stone's Cold-Pressed Single-Estate Extra Virgin Olive Oil — Marrakech (500ml) is available as a limited single-harvest batch from our product page, with fulfilment in the UK, EU, and US. Elsewhere, look for extra virgin grade, dark glass and a clear origin.
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
The research on olive oil and diabetes is better than most food-and-health stories: a randomised trial subgroup, large cohort studies and two meta-analyses, all broadly agreeing that extra virgin olive oil, used in place of other fats within a Mediterranean-style diet, is associated with a lower risk of type 2 diabetes and slightly better glucose control. That is worth knowing.
It is also worth keeping in proportion. The effects are modest, much of the evidence is observational, and none of it suggests olive oil can do the job of medication or of the wider changes — weight, activity, overall diet — that matter most. Use it as your everyday fat, choose a genuine extra virgin oil, and keep your GP or diabetes team in the loop.
Our Cold-Pressed Single-Estate Extra Virgin Olive Oil — Marrakech — 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.
Disclaimer: This article summarises published research on olive oil and blood sugar at the time of writing; research findings and product details may change, and readers should check current sources. It is not medical advice. If you have diabetes or prediabetes, speak to your GP or diabetes team before making significant changes to your diet, and never change or stop medication without their advice. 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.