In short:
Experts at MasWorth look at what the research says about extra virgin olive oil, blood sugar and metabolic health, including where the evidence is still mixed.
Is olive oil good for diabetes?
There’s plenty of research looking at the relationship between olive oil and diabetes - but the details matter, and some of the findings are more encouraging than others.
Olive oil has been widely studied in relation to diabetes, particularly its effects on blood sugar response, insulin sensitivity and heart health. What the research doesn't support, however, is treating it as a supplement or quick fix.
In this article, we’ll look at what the science actually says, the difference extra virgin olive oil can make, how much is typically used in studies, and what to keep in mind if you’re managing diabetes.
Why fat quality matters in type 2 diabetes
In Crete, nobody sits down to lunch and thinks about their glycaemic index (a measure of how quickly food raises blood sugar). They drizzle olive oil over their Γίγαντες (gigantes), tear off some bread, and get on with it. Yet the rates of type 2 diabetes across traditional Mediterranean populations are - and have long been - notably lower than in much of the Western world.
Nutritional science has spent decades trying to work out why, and much of it comes back to insulin resistance: cells stop responding normally to insulin, blood sugar rises, and over time that damages blood vessels, nerves, and organs.
Diet has a real influence on insulin resistance. Diets higher in refined carbohydrates and saturated fats tend to make it worse, while Mediterranean-style diets, rich in vegetables, legumes, whole grains, and olive oil as the main fat, are consistently linked with better metabolic health.
This is where extra virgin olive oil enters the story. In Crete, it isn’t treated as a supplement or a “health food” on the side - it’s the default fat used in everyday cooking. Chemically, that matters.
High-quality EVOO is rich in polyphenols such as hydroxytyrosol, oleocanthal, and oleacein, which have been widely studied for their antioxidant and anti-inflammatory properties.
So what’s the connection here? Insulin resistance is linked with chronic inflammation and oxidative stress, which is one reason researchers are interested in the biological effects of olive oil polyphenols.
What does the research say about extra virgin olive oil and diabetes?
Researchers have looked at EVOO in relation to blood sugar, inflammation and heart health, particularly when it forms part of a Mediterranean-style diet.
Blood sugar and insulin response
Some studies suggest that adding EVOO to a meal can change the post-meal blood sugar response.
In a small randomised controlled trial involving people with type 1 diabetes, a high-glycaemic meal eaten with extra virgin olive oil led to lower post-meal blood sugar and a more balanced insulin response compared with butter or a low-fat alternative. A separate metabolic trial published in Nutrition & Diabetes comparing EVOO with corn oil found similar results.
Longer-term research is less clear. Some studies have reported improvements in measures such as fasting blood sugar and HbA1c (a long-term blood sugar marker), while others have found little or no significant change.
While the short-term response to a meal is an interesting area of research, we can't draw the same straightforward conclusion about longer-term blood sugar control.
Reducing inflammation and oxidative stress
Extra virgin olive oil contains polyphenols, including oleocanthal - the compound behind the peppery finish in good olive oil. Oleocanthal has been studied for its effects on inflammatory pathways, including pathways involved in insulin resistance.
One randomised crossover study in adults with prediabetes compared a polyphenol-rich extra virgin olive oil with a standard version of olive oil. The higher-polyphenol oil led to improvements in markers of inflammation and antioxidant status.
It’s one reason researchers are interested in the polyphenol content of EVOO, although it’s still difficult to separate their effects from everything else happening in the diet.
Heart health (critical for diabetics)
Type 2 diabetes significantly increases the risk of heart disease and stroke, which is why the cardiovascular evidence for EVOO matters so much here.
A 2025 review in Nutrients reported improvements in blood pressure, cholesterol balance, inflammation and blood vessel function among people consuming EVOO daily. Some of the research included people with prediabetes, type 2 diabetes or high cardiovascular risk.
Longer-term data points in a similar direction. A large cohort study of adults at high cardiovascular risk found that higher olive oil intake was linked with around a 35–40% lower risk of cardiovascular disease and nearly 50% lower cardiovascular mortality. However, this was a high-risk adult population rather than a study specifically looking at people with type 2 diabetes.
So while the cardiovascular evidence around olive oil is encouraging, we can’t assume that the same figures apply specifically to people with diabetes. Much of the research looks at broader cardiovascular risk or at olive oil as part of a wider Mediterranean-style diet.
When olive oil might not help
Olive oil still carries energy (around 120 kcal per tablespoon), so adding it on top of an unchanged diet can tip total intake upwards, which can worsen insulin resistance over time.
Because olive oil is still energy-dense, it makes more sense to think about what it replaces in the diet rather than simply adding extra oil on top.
And to be clear: EVOO is supportive - it isn’t a replacement for prescribed medication or glucose monitoring.
How EVOO fits into a Mediterranean-style diet
Much of the research on EVOO and metabolic health looks at it as part of a Mediterranean-style diet, where olive oil is used regularly as the main added fat. In everyday cooking, that can look like:
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Dress salads and non-starchy vegetables with EVOO and lemon or vinegar instead of creamy dressings
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Finish beans, lentils, and whole grains with EVOO
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Swap butter on bread with EVOO
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Drizzle olive oil over fish, chicken, or roasted vegetables once they’re cooked
There isn’t a magic amount of EVOO for managing diabetes. In studies, olive oil is generally included as part of the overall diet rather than taken as a supplement, so the bigger picture matters more than hitting a particular number each day.
Does the type of olive oil matter?
Not all olive oil behaves the same in the body.
Extra virgin olive oil is cold-pressed and minimally processed, which keeps its natural polyphenols intact. Refining removes many of the naturally occurring polyphenols found in extra virgin olive oil.
There’s also a quality gap within EVOO itself. Oils containing at least 250 mg/kg of the relevant olive oil polyphenols can meet the condition for the authorised polyphenol health claim, but many supermarket oils don’t publish their polyphenol levels at all, making comparison difficult. This is something we’ve written about in detail in our Ultimate Guide to High Polyphenol Olive Oil in the UK, and it matters more than most people realise.
Some extra virgin olive oils are simply higher in polyphenols than others - for example, MasWorth Family Groves EVOO at 965 mg/kg, and November Polyphenols EVOO at 1200+ mg/kg - both early-harvest, cold-pressed oils, each backed by certified polyphenol testing:
The bottom line
There’s plenty of interesting research around olive oil and diabetes, but it doesn’t give us a simple yes-or-no answer. Some studies have found encouraging results around blood sugar and cardiovascular health, while longer-term research is less consistent.
What we do know is that EVOO has a natural place in Mediterranean-style cooking, particularly when it replaces less healthy fats. And if polyphenols are part of the reason researchers keep coming back to EVOO, knowing what’s actually in the bottle is a good place to start.
That's why MasWorth focuses on early-harvest production, independent lab testing, and publishing polyphenol figures directly - so you can see exactly what’s in the bottle, not just marketing claims.
For people who use it daily, our high polyphenol olive oil subscription options make it simpler to keep a steady supply without thinking about it. They offer regular access to the same tested oils, delivered as part of a routine rather than a one-off purchase.
Olive Oil And Diabetes FAQs
Does olive oil lower blood sugar?
Some studies have found that olive oil can change the blood sugar response to a meal, but the evidence around longer-term blood sugar control is less clear. A 2025 review of randomised trials found no significant overall effect on blood glucose or HbA1c.
Is extra virgin olive oil good for diabetes?
EVOO can be part of a balanced Mediterranean-style diet, but research doesn't give us a simple answer about its specific effects on diabetes. Its fats and polyphenols are still being studied for their potential role in metabolic and cardiovascular health.
Does the type of olive oil matter?
Extra virgin, with a published polyphenol figure. Some studies have specifically investigated polyphenol-rich EVOO, including early-harvest oils, and this is one reason polyphenol content has become such an interesting area of research. If the bottle doesn't publish a mg/kg figure, you're largely guessing at the polyphenol content.
How much olive oil is typically used in studies?
Studies use a range of amounts, so there isn’t a single amount specifically recommended for diabetes. Around 1–3 tablespoons a day appears in a number of intervention studies, but the wider diet matters just as much as the amount of oil used.
Are olives good for diabetics too?
They offer some similar benefits from their fat and polyphenol content, but the evidence is stronger and more consistent for olive oil than whole olives. If you're eating jarred or brined olives, watch the sodium content - that's worth factoring in if you're managing blood pressure alongside diabetes!
Scientific & Nutritional Information
The information on this website is provided for educational and informational purposes only and summarises published scientific research and general nutritional information relating to olive oil and olive polyphenols. It is not intended as medical, nutritional or dietary advice and should not be relied upon as a substitute for advice from your doctor, registered dietitian or other qualified healthcare professional.
Scientific studies reflect the findings of their respective authors and should not be interpreted as evidence that the same results will occur for every individual or from the consumption of any particular product.
Any health claims made in relation to our products are limited to those expressly authorised under applicable UK and EU nutrition and health claims legislation.
