Researchers combined results from 51 scientific studies involving over 4,300 people to see if olive oil helps control blood sugar and insulin levels. While olive oil didn’t significantly change overall blood sugar or insulin levels, the analysis found something interesting: taking 25-50 grams of olive oil daily (about 2-3 tablespoons) may help improve how well the body uses insulin. This suggests olive oil might have a small benefit for people managing diabetes, but more research is needed to confirm how helpful it really is in everyday life.

The Quick Take

  • What they studied: Whether different types of olive oil help people control their blood sugar and improve how their body handles insulin
  • Who participated: Over 4,300 adults across 51 different research studies. The studies tested various amounts of olive oil over different time periods
  • Key finding: Olive oil didn’t significantly lower blood sugar or insulin levels overall. However, taking 25-50 grams daily showed promise for improving insulin resistance (how well the body uses insulin)
  • What it means for you: Olive oil alone probably won’t dramatically improve blood sugar control, but it may offer modest benefits when used in the right amount. It’s not a replacement for diabetes medications or lifestyle changes, but it could be part of a healthy diet

The Research Details

Scientists searched three major medical databases and found 2,705 articles about olive oil and blood sugar. They carefully reviewed 115 full articles and selected 51 high-quality studies that tested olive oil’s effects on blood sugar control. These 51 studies included 4,334 people total. The researchers combined all the results using statistical methods to see if olive oil had consistent effects across different studies. They also looked at whether the amount of olive oil or how long people used it made a difference.

By combining many smaller studies into one large analysis, researchers can see patterns that might not show up in individual studies. This approach is stronger than looking at just one study because it reduces the chance that random results skew the findings. The researchers also looked at dose-response relationships, meaning they checked if using more olive oil or using it longer changed the results.

This is a systematic review and meta-analysis, which is considered one of the strongest types of research. The researchers registered their plan ahead of time (PROSPERO registration), which prevents them from changing their methods based on results. They assessed study quality using GRADE methods, a respected system for evaluating evidence. However, the studies they reviewed showed some inconsistency in their results, suggesting that factors like olive oil type, study duration, and participant differences may matter.

What the Results Show

When researchers combined all 51 studies, olive oil consumption did not significantly change fasting blood sugar levels, insulin levels, or HbA1c (a measure of average blood sugar over 3 months). These results were consistent across most studies, meaning the lack of effect wasn’t due to random chance. However, the story became more interesting when researchers looked at specific doses and time periods. A daily dose of 25-50 grams of olive oil (roughly 2-3 tablespoons) showed a significant improvement in HOMA-IR, which measures how well the body’s cells respond to insulin. This suggests that the amount of olive oil and how long someone uses it may matter more than whether they use it at all.

The dose-response analysis revealed nonlinear relationships, meaning the benefits don’t increase steadily with more olive oil. Instead, there appears to be an optimal range (25-50 grams daily) where benefits are most noticeable. The duration of olive oil use also showed a nonlinear relationship with insulin resistance, insulin levels, and HbA1c, suggesting that benefits may appear at certain time points rather than continuously increasing over time.

Previous research suggested olive oil might help with blood sugar control because it contains healthy fats and compounds with anti-inflammatory properties. This meta-analysis confirms that while olive oil is a healthy food, its direct effect on blood sugar control is modest. The findings align with the broader understanding that olive oil is beneficial as part of a Mediterranean diet, but it’s not a standalone diabetes treatment.

The studies reviewed had different designs, used different types of olive oil (refined vs. extra virgin), tested different doses, and lasted different lengths of time. This variation made it harder to draw firm conclusions. Some studies had small numbers of participants, and not all studies measured the same outcomes. The high variability in insulin measurements (I² = 91.49%) suggests that factors beyond olive oil type influenced results. Additionally, most participants were adults without diabetes, so results may not apply to people with diagnosed diabetes.

The Bottom Line

Based on moderate-quality evidence, olive oil can be part of a healthy diet. If you’re interested in potential blood sugar benefits, consuming 25-50 grams daily (about 2-3 tablespoons) appears most promising. However, olive oil should not replace diabetes medications or other proven treatments. It works best as part of an overall healthy lifestyle including regular exercise, balanced meals, and stress management. Confidence level: Moderate (the evidence suggests a benefit, but more research is needed)

This research is relevant for people managing blood sugar, those at risk for diabetes, and anyone interested in the health benefits of olive oil. It’s especially useful for people following Mediterranean diets. However, these findings don’t apply to people with severe diabetes complications or those taking specific medications that interact with olive oil. People with olive allergies should obviously avoid it

If olive oil has benefits for insulin resistance, improvements would likely appear gradually over weeks to months of consistent use, not immediately. Most studies lasted several weeks to months, so patience is important when evaluating any effects

Want to Apply This Research?

  • Track daily olive oil intake in grams or tablespoons, aiming for 25-50 grams daily. Also monitor fasting blood sugar levels weekly if you have a glucose meter, and record energy levels and hunger patterns to notice any changes
  • Add olive oil to meals in measured amounts: use it for salad dressings, drizzle on cooked vegetables, or use it for low-heat cooking. Set a daily reminder to consume your target amount and log it in the app to build consistency
  • Track olive oil consumption weekly and compare it to blood sugar readings or energy levels over 8-12 week periods. Note any patterns between consistent olive oil use and how you feel. If you have access to HbA1c tests, compare results every 3 months

This research summary is for educational purposes only and should not replace professional medical advice. Olive oil is a food, not a medicine, and cannot replace diabetes medications or medical treatment. If you have diabetes or prediabetes, consult your doctor or registered dietitian before making significant dietary changes. This meta-analysis shows modest effects, and individual results may vary. People taking blood-thinning medications or with certain health conditions should discuss olive oil consumption with their healthcare provider before making changes to their diet.