In short:
Research into olive oil and diabetes is growing, but the findings remain mixed, with some studies reporting changes in blood sugar, insulin resistance or diabetes risk and others finding little or no significant effect. Overall, there’s enough evidence to keep investigating the relationship, but not enough to support claims that olive oil prevents or manages diabetes.
Olive oil, blood sugar and metabolic health
Olive oil is often mentioned alongside the Mediterranean diet, heart health and healthy ageing. But what about diabetes? There’s plenty of interest in whether extra virgin olive oil might help with blood sugar control, insulin sensitivity or the risk of developing type 2 diabetes. The problem is that the answer isn’t quite as clear-cut as some claims make it sound.
There’s good reason for the interest. Olive oil contains monounsaturated fats and a range of phenolic compounds, while research has linked the Mediterranean diet with better metabolic health - but that doesn’t necessarily mean olive oil itself can prevent or manage diabetes.
To understand what the research is really telling us, we need to look a little more closely at what different studies are actually measuring - and what the results actually show. That’s what we’re going to do today.
Research notice
There’s an important distinction to make before we get into the research. The only authorised UK and EU health claim for olive oil polyphenols relates to the protection of blood lipids from oxidative stress. It doesn’t cover blood sugar, insulin sensitivity or diabetes.
The studies below explore these areas as part of ongoing scientific research. They’re interesting findings, but they shouldn’t be taken as evidence that olive oil or any olive oil product can treat or manage diabetes.
If you’d like to understand more about the authorised claim, including the required daily intake and the research behind it, you can read our guides to buying high polyphenol olive oil and olive oil and cholesterol.
What does the latest research actually tell us?
We’ve looked at six recent studies, each approaching the relationship between olive oil, diet and diabetes from a slightly different angle. Individually, each one measures something slightly different, in a different population, with different strengths and different blind spots; together, they give us a better sense of where the evidence is convincing, where it gets more complicated, and what we still don’t know.
1. Takhttavous et al. (2026): Olive oil, glucose control and insulin resistance
The researchers combined 51 trials, involving 4,334 adults, to see whether olive oil affects four measures of glucose control: fasting glucose, insulin, HbA1c (average blood sugar over the previous two to three months) and HOMA-IR (a measure of insulin resistance).
They also looked at whether the amount of olive oil consumed and the length of the intervention changed the results. Because the review also used the GRADE system to assess the quality of the evidence, it gives us a better idea of how much confidence we can have in its findings.
What they found: The headline result isn’t particularly exciting: across all 51 trials, olive oil had no significant effect on any of the four measures. But look more closely and things get a little more interesting.
When the researchers analysed intake by dose, consuming 25-50g of olive oil a day was associated with a significant improvement in HOMA-IR, suggesting the body was responding to insulin more effectively. Longer studies also showed significant improvements in insulin and HbA1c - something that wasn’t seen in shorter studies.
What does this mean? It would be easy to focus on the promising dose-response result and overlook the overall finding - but both are important. The honest takeaway is two-sided: olive oil didn’t significantly improve glucose control across all 51 trials, but there was a real dose-dependent effect at higher intakes that only showed up once participants were consuming a meaningful daily amount, over a meaningful stretch of time.
2. Zou & Liu (2025): Olive oil and diabetes-related outcomes
This 2025 umbrella review brought together 19 systematic reviews and meta-analyses looking at olive oil, diabetes and related metabolic outcomes. Rather than analysing individual trials, the researchers looked across existing reviews to see what the wider body of research was showing.
What they found: The researchers found a link between olive oil consumption and a lower risk of type 2 diabetes. They also found links between olive oil consumption and changes in HbA1c, fasting glucose, insulin and insulin resistance.
But there’s an important caveat. When the researchers assessed the certainty of the evidence using the GRADE system, 77% of the evidence was rated as low or moderate certainty - meaning we can't be as confident in those findings as we would be with higher-certainty evidence. So while the findings are interesting, they’re not strong enough to give us a clear answer.
How it compares with other research: When we put this alongside the 51-trial meta-analysis, the findings aren’t as contradictory as they might first seem. Zou and Liu found links between olive oil consumption and several diabetes-related outcomes, but much of the underlying evidence was rated as low or moderate certainty.
Takhttavous et al. found no significant effect across all 51 trials, but did identify a positive signal at higher intakes and over longer periods. Together, the studies suggest there may be more to explore around how much olive oil is consumed and for how long - but the evidence isn’t strong enough to draw firm conclusions.
3. Jawerbaum et al. (2026): OLIDIAG: Extra virgin olive oil and gestational diabetes
The OLIDIAG study took a more specific approach than the two reviews above. This randomised controlled trial, carried out across several research sites, followed 190 women with gestational diabetes to investigate whether adding extra virgin olive oil to their diet affected pregnancy and metabolic outcomes.
Women in the intervention group were advised to consume three tablespoons of EVOO a day, putting their intake roughly within the 25-50g range highlighted in the Takhttavous meta-analysis.
What they found: The women who consumed EVOO were less likely to need insulin treatment during pregnancy. They also had lower triglyceride levels, with a difference of 43.3 mg/dL between the groups - and fewer babies were born with more than one complication. Gestational weight gain didn't differ between groups, so the effect wasn't simply about eating more or less overall.
How it compares with other research: The amount of EVOO used in this trial is particularly interesting when compared with the Takhttavous study. Three tablespoons a day falls within the 25-50g daily intake where Takhttavous et al. found a significant improvement in HOMA-IR.
Unlike the reviews, this was a single trial looking at a specific group of people and a specific amount of EVOO. That makes the findings more focused, but it also means we can’t assume the same results would apply to people without gestational diabetes. For now, it adds another interesting piece to the research rather than providing a definitive answer.
4. Du & Zhou (2025): Exploring olive oil consumption and diabetes risk
This 2025 dose-response meta-analysis looked at whether the amount of olive oil people consumed was linked to their risk of developing diabetes. The researchers brought together 10 studies, including four cohort studies and six randomised controlled trials, involving more than 500,000 participants. They also looked at whether diabetes risk changed depending on how much olive oil people consumed.
What they found: People with the highest olive oil consumption had a 13% lower risk of developing type 2 diabetes in the cohort studies and a 22% lower risk in the randomised controlled trials, compared with those with the lowest intake. The researchers also found a statistically significant association at around 10-20g of olive oil per day in their dose-response analysis. A similar pattern was seen when they looked specifically at extra virgin olive oil.
How it compares with other research: The amount of olive oil consumed stands out when we compare this study with the Takhttavous analysis. Du & Zhou found a significant association with diabetes risk at around 10-20g per day, while Takhttavous et al. found an improvement in HOMA-IR at around 25-50g per day.
These studies were measuring different things, so the results can’t be used to suggest that there is a specific amount of olive oil that works for diabetes - but both findings suggest that the amount consumed may be an important factor worth investigating further.
5. Figueiredo-González et al. (2025): OILDIABET: High-Polyphenol EVOO and Type 2 Diabetes
The 2025 OILDIABET trial looked specifically at 116 adults with type 2 diabetes. Participants consumed 30 mL of high-polyphenol EVOO each day for 24 weeks, while the control group was advised to minimise EVOO and use refined olive oil instead. Researchers measured several markers of glucose control, including fasting glucose, HbA1c, fasting insulin and HOMA-IR.
What they found: Across the full group, the EVOO intervention significantly reduced HOMA-IR, but there was no significant difference in fasting glucose between the two groups. The researchers also reported greater changes in some subgroups, including improvements in fasting glucose and HbA1c among participants with obesity, while people who started with higher insulin resistance showed improvements in insulin and HOMA-IR. These subgroup findings should be treated with some caution because they involved fewer people.
How it compares with other research: OILDIABET gives us a closer look at high-polyphenol EVOO in people with type 2 diabetes. Like the Takhttavous analysis, it didn’t find improvements across all of the blood sugar measures tested, although HOMA-IR did improve. The results are interesting, but more research is needed to understand whether these effects can be seen consistently in people with type 2 diabetes.
6. Galang et al. (2020): Extra virgin olive oil and post-meal blood sugar in type 2 diabetes
This small randomised crossover trial looked at what happened to blood glucose after a meal containing extra virgin olive oil. The study included 13 people with type 2 diabetes, who ate the same meal on two separate occasions: once with a tablespoon of EVOO and once without it. Researchers then measured their blood glucose levels over the following two hours.
What they found: The meal containing EVOO resulted in a greater increase in blood glucose after two hours than the meal without EVOO. In other words, adding a tablespoon of EVOO to this particular meal didn't produce a lower post-meal glucose response.
How it compares with other research: This is a very different type of study from the larger reviews above. It looked at what happened after one meal, in just 13 people, rather than following people over weeks or months. Its findings also don't match the more promising signals seen in some of the other research, including the improvement in HOMA-IR seen in OILDIABET.
That doesn't mean one study cancels out the other - they were asking different questions, using different amounts and types of olive oil, and measuring different outcomes. It’s a useful reminder that the results of one study don’t necessarily tell us what to expect in another, particularly when the type and amount of olive oil and the length of the study are different.
What does the research tell us so far?
When you put these studies side by side, there isn't one clear pattern running through all of them. Some findings are encouraging, others are neutral, and some point in different directions. That's not necessarily a problem with the research - it's a reflection of how complicated it is to study diet and diabetes.
So where does that leave us? The research is interesting, but it isn't strong or consistent enough to support broad claims about olive oil and diabetes. The more promising findings around insulin resistance, diabetes risk and higher olive oil intakes give researchers useful areas to investigate, but they don't yet tell us exactly when olive oil might offer benefits for people with diabetes, or who might benefit most.
It’s also important to separate what the research is investigating from what can actually be claimed about olive oil. There are currently no authorised UK or EU health claims stating that olive oil or olive oil polyphenols reduce blood sugar, improve insulin sensitivity or help manage diabetes.
Olive oil can still have a place in a balanced, diabetes-aware diet, while we wait for stronger evidence about its specific role in blood sugar control.
If you're wondering what that can look like in practice, our guide to EVOO and diabetes looks at how to include it as part of your diet. And if you want to explore the wider research around olive oil, take a look at our guide to olive oil and cardiovascular health or explore the blog for more research and insights.
Frequently Asked Questions
What are the benefits of olive oil for diabetes?
EVOO can form part of a balanced diet for people with diabetes. However, research into the specific extra virgin olive oil benefits for diabetes has produced mixed results, with some studies reporting changes in measures such as insulin resistance and HbA1c, while others have found little or no significant effect. There are currently no authorised UK or EU health claims stating that olive oil treats or helps manage diabetes.
Does olive oil lower blood sugar?
The research so far doesn't give us a clear answer. Some studies have found changes in measures such as insulin resistance or HbA1c, while others have found no significant effect on blood sugar. More research is needed before firm conclusions can be drawn.
Why do scientists study olive oil and glucose metabolism?
Researchers are interested in how dietary fats and naturally occurring compounds in foods may affect processes involved in glucose regulation and insulin signalling. Olive oil contains monounsaturated fats and phenolic compounds, making it an area of ongoing nutrition research.
Are olive oil polyphenols being studied?
Yes. Researchers are investigating olive oil polyphenols in relation to glucose metabolism and other areas of health, including cardiovascular health, cognitive function, inflammation and oxidative stress. However, research into these potential effects is still developing.
Scientific references
Scientific and nutritional information disclaimer
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.
