Researchers are testing whether extra virgin olive oil might help prevent preeclampsia, a serious pregnancy condition that affects blood pressure and can be dangerous for both mom and baby. In this study, 156 pregnant women at high risk will either drink a small amount of special olive oil daily or follow standard pregnancy nutrition guidelines. Scientists believe olive oil’s natural protective compounds might reduce the inflammation and blood vessel damage that causes preeclampsia. If this pilot study shows promise, it could lead to a simple, natural way to help protect high-risk pregnancies.
The Quick Take
- What they studied: Whether drinking extra virgin olive oil during pregnancy can reduce the risk of preeclampsia (a serious condition with high blood pressure) and other pregnancy complications
- Who participated: 156 pregnant women between 8-16 weeks of pregnancy who are at higher risk for preeclampsia, split into two equal groups of 78 women each
- Key finding: This is a pilot study (early-stage research), so results aren’t available yet. Researchers will compare pregnancy outcomes between women who drink olive oil daily and those who follow standard nutrition advice
- What it means for you: This research is still in progress and hasn’t produced results yet. If successful, it may eventually offer pregnant women a simple dietary option to reduce serious pregnancy risks, but more research is needed before any recommendations can be made
The Research Details
This is a randomized controlled trial, which is considered one of the strongest types of medical research. Researchers will randomly assign 156 pregnant women into two groups: one group will consume 42 milliliters (about 3 tablespoons) of early-harvested extra virgin olive oil daily for 4 weeks, while the other group will follow standard pregnancy nutrition guidelines without the olive oil. Both groups will receive low-dose aspirin if their doctors recommend it for pregnancy safety.
The study takes place at Barzilai University Medical Center and focuses on women between 8-16 weeks of pregnancy who have risk factors for preeclampsia. Researchers will track how well women stick to the olive oil routine through phone calls and by measuring special compounds in their blood that show whether they’re actually consuming the olive oil.
The study is “single-masked,” meaning the researchers analyzing the data won’t know which women received olive oil and which didn’t, which helps prevent bias in the results.
Preeclampsia is a serious pregnancy condition that can harm both mother and baby, yet doctors currently have few dietary ways to prevent it. This study design is important because it tests a real-world intervention (eating olive oil) in women who actually need it. By measuring blood markers of inflammation and damage, researchers can understand whether olive oil actually works the way they think it does.
This is a pilot study, meaning it’s designed to test whether the idea is worth studying on a larger scale rather than to prove olive oil works. The study uses randomization (random assignment to groups), which reduces bias. The single-masked design for data analysis also strengthens reliability. However, with only 78 women per group, this study is too small to prove whether olive oil truly prevents pregnancy complications—it can only suggest whether larger studies are worthwhile.
What the Results Show
This is a protocol paper describing the planned study, not actual results. The researchers have not yet completed the study or collected data. The study is designed to measure five main pregnancy outcomes: whether women develop gestational diabetes (high blood sugar during pregnancy), preeclampsia (high blood pressure with protein in urine), need for cesarean delivery, early birth, and whether babies are smaller than expected for their age.
The study will also measure secondary outcomes including blood sugar levels, special blood markers that indicate placental health (sFlt-1/PlGF ratio), blood pressure throughout pregnancy, and how well babies grow. Researchers will collect blood samples at the start and after 4 weeks to measure vitamin D levels, placental health markers, and compounds from the olive oil that show up in the bloodstream.
Beyond the main pregnancy outcomes, the study will track maternal blood pressure changes, the exact timing of delivery, and newborn growth measurements. These secondary measures help researchers understand whether any benefits from olive oil work through specific biological pathways (like reducing inflammation) or through other mechanisms.
Current medical practice uses low-dose aspirin for some high-risk pregnancies to prevent preeclampsia, but dietary approaches are limited. This study builds on earlier research showing that olive oil contains powerful antioxidant compounds that reduce inflammation and protect blood vessels. The focus on early-harvested olive oil is newer, as this type contains higher levels of protective compounds than regular olive oil.
This is a pilot study with a relatively small sample size (156 women total), so it cannot definitively prove that olive oil prevents pregnancy complications. The study only lasts 4 weeks, which may not be long enough to see all potential benefits. The study takes place at one medical center in Israel, so results may not apply to all populations. Additionally, the study relies on women remembering to take the olive oil daily, which can affect results if some women don’t follow instructions consistently.
The Bottom Line
No clinical recommendations can be made yet, as this study has not been completed. Pregnant women should not change their diet based on this protocol alone. Women at high risk for preeclampsia should follow their doctor’s current recommendations, which may include low-dose aspirin and regular monitoring. Once this pilot study is completed and larger studies are conducted, dietary recommendations may change.
This research is most relevant to pregnant women identified as high-risk for preeclampsia, their obstetricians, and maternal health researchers. Women with normal pregnancies should not assume olive oil will provide special benefits. This study is not appropriate for women who are allergic to olives or have other contraindications.
This is a pilot study still in progress. Even after completion, results will need to be published and reviewed by other scientists. If promising, larger studies would likely take 2-5 years. Clinical recommendations would only emerge after multiple studies confirm benefits, which could take 5-10 years from now.
Want to Apply This Research?
- Once results are available and if recommendations change, users could track daily olive oil consumption (measured in tablespoons) and correlate it with blood pressure readings taken at home, which are important for monitoring pregnancy health
- If future research supports olive oil for pregnancy health, users could set daily reminders to consume the recommended amount and log completion. The app could provide recipes or simple ways to incorporate olive oil into meals
- Long-term tracking would involve monitoring blood pressure trends throughout pregnancy, tracking adherence to dietary recommendations, and noting any pregnancy complications. This data could be shared with healthcare providers to support personalized pregnancy care
This article describes a research study protocol that has not yet been completed or published with results. This is not medical advice. Pregnant women, especially those at high risk for preeclampsia, should not make dietary changes based on this protocol alone. All pregnancy-related decisions should be made in consultation with your obstetrician or midwife. Do not use olive oil as a substitute for medical treatments or monitoring recommended by your healthcare provider. If you are pregnant and have concerns about preeclampsia risk, discuss evidence-based prevention strategies with your doctor.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.