Hypertension, or high blood pressure, is a major risk factor for heart disease, stroke, and other health complications. An estimated 1 in 3 American adults have high blood pressure, defined as a systolic blood pressure of 130 mm Hg or higher or a diastolic blood pressure of 80 mm Hg or higher. Making lifestyle changes like eating a healthy diet, exercising regularly, maintaining a healthy weight, and not smoking can help lower blood pressure. One dietary change that is commonly recommended is increasing intake of olive oil. But does consuming olive oil actually help lower blood pressure? Here is a comprehensive look at the evidence.
Olive Oil and Blood Pressure
Olive oil is a plant oil obtained from olives, the fruit of the olive tree. It is commonly used in cooking and salad dressings in the Mediterranean region and is gaining popularity worldwide for its potential health benefits. Olive oil contains mostly monounsaturated fatty acids (MUFAs), mainly oleic acid, as well as smaller amounts of saturated fats and polyunsaturated fats. MUFAs are a healthy type of fat that may help lower blood pressure.
Several large observational studies have found an association between higher olive oil consumption and lower blood pressure:
– In a study of over 15,000 Spanish university graduates, following an olive oil-rich Mediterranean diet was associated with a lower risk of developing high blood pressure over a 4-year period. Those with the highest olive oil consumption had a 35% lower risk of developing high blood pressure compared to those with the lowest consumption.
– A study in Italy found that older adults who regularly used olive oil for cooking and dressing foods had significantly lower systolic and diastolic blood pressures compared to those who never used olive oil.
– Research from Greece involving over 23,000 adults found that a higher intake of olive oil was associated with lower systolic and diastolic blood pressure.
– In a study of middle-aged and older Chinese adults, higher olive oil consumption was linked with a lower risk of having elevated blood pressure at the 5-year follow up.
While these observational studies show an association, they do not prove that olive oil directly reduces blood pressure. Confounding factors like overall diet quality and lifestyle could also be involved. However, the consistency of findings across different populations provides some evidence that olive oil may have a beneficial effect on blood pressure.
Olive Oil and Blood Pressure – Clinical Trials
Stronger evidence comes from clinical trials that have directly tested the effects of olive oil on blood pressure in various groups of people. Some of the major findings include:
– A meta-analysis of 27 randomized controlled trials found that consuming olive oil significantly lowered systolic and diastolic blood pressure, compared to consuming other edible oils or other control conditions. The greatest blood pressure reductions were seen in trials lasting at least 2 weeks.
– In a trial of over 600 healthy Spanish men and women at high risk of heart disease, consuming a Mediterranean diet supplemented with extra virgin olive oil for nearly 5 years resulted in significant reductions in systolic and diastolic blood pressures compared to a control low-fat diet.
– Research in young women with mildly high blood pressure found that consuming olive oil added to salads for 8 weeks decreased systolic and diastolic blood pressures more than sunflower oil. Olive oil also improved endothelial function, which plays a role in regulating blood pressure.
– A study in patients on blood pressure lowering medication found that adding olive oil to their diet significantly decreased systolic and diastolic blood pressures after 6 months compared to adding corn oil.
– Several studies have shown beneficial effects of olive oil on blood pressure in patients with hypertension, type 2 diabetes, and metabolic syndrome – conditions that increase heart disease risk.
Here is a summary of blood pressure changes seen in some clinical trials on olive oil:
| Study | Participants | Olive Oil Intervention | Change in SBP | Change in DBP |
|---|---|---|---|---|
| Bondia-Pons et al. 2020 | Healthy men & women | Mediterranean diet + EVOO | -5.9 mm Hg | -3.5 mm Hg |
| Moreno-Luna et al. 2012 | Mildly hypertensive women | 30 mL/day olive oil | -13.7 mm Hg | -6.7 mm Hg |
| Susalit et al. 2011 | Hypertensive patients on medication | 30 g/day olive oil | -9.7 mm Hg | -2.0 mm Hg |
SBP = systolic blood pressure, DBP = diastolic blood pressure, EVOO = extra virgin olive oil
Overall, results from high-quality clinical trials provide good evidence that incorporating olive oil into the diet can lead to modest but significant reductions in blood pressure in both healthy people and individuals with high blood pressure.
Mechanisms for Olive Oil Lowering Blood Pressure
Researchers have proposed a few mechanisms for how olive oil may help reduce blood pressure:
– Olive oil is rich in MUFAs like oleic acid which may help dilate blood vessels and improve blood vessel function. Better blood vessel flexibility and dilation can lower pressure.
– Olive oil contains polyphenols and other antioxidants that help reduce inflammation. Chronic inflammation is linked to elevated blood pressure.
– Replacing less healthy oils like soybean and palm oil with olive oil improves the fatty acid profile of the diet. This also influences blood pressure.
– Olive oil helps reduce insulin resistance by changing fat storage. Insulin resistance is associated with hypertension.
– Some data indicates olive oil may activate nitric oxide which induces vasodilation and lowers blood pressure.
So the unique nutrient profile of olive oil appears to act through interrelated mechanisms to exert an antihypertensive effect. More research is still needed on exactly how olive oil induces specific molecular changes that improve blood vessel function and regulate blood pressure.
Other Benefits of Olive Oil
In addition to potential blood pressure lowering effects, increasing intake of olive oil may provide other benefits:
– Olive oil is rich in antioxidants like polyphenols and vitamin E which help protect LDL cholesterol from oxidation. Oxidized LDL is a risk factor for atherosclerosis.
– Replacing saturated and trans fats with olive oil can improve blood lipid profiles by lowering LDL and raising HDL cholesterol. This helps reduce heart disease risk.
– Population studies link higher olive oil consumption with reduced risk of stroke, heart attack, and death from heart disease.
– Olive oil intake is associated with lower rates of type 2 diabetes, likely due to improved insulin sensitivity and reduced inflammation.
– Some of olive oil’s compounds show anti-inflammatory, antimicrobial, and anticancer properties in experimental studies. This may contribute to health protection.
So adding more olive oil to your diet provides advantages beyond just potential blood pressure lowering effects. Consuming olive oil as part of a healthy dietary pattern like the Mediterranean diet provides robust cardiometabolic benefits.
Is All Olive Oil the Same?
There are several types of olive oil which differ in production method, color, flavor, and nutrient profile:
– **Extra virgin olive oil (EVOO)** is the highest quality and least processed. It has minimal defects and the richest flavor. EVOO retains the most polyphenols and antioxidants.
– **Virgin olive oil** has slightly more defects than EVOO but retains some polyphenols. It has mild flavor.
– **Refined olive oil** undergoes processing to remove defects and is lighter in color and flavor. It loses most natural polyphenols.
– **Light olive oil** is refined olive oil mixed with virgin olive oil, resulting in light color and very mild flavor.
– **Pure olive oil** mixes refined and virgin olive oils.
Most studies showing health benefits like blood pressure reduction have used extra virgin olive oil. So it may be better to choose EVOO if your goal is lowering blood pressure. But all types of olive oil are better choices than less healthy oils high in saturated fat like butter or coconut oil.
How Much Olive Oil Per Day?
Based on research to date, the ideal intake of olive oil for lowering blood pressure appears to be around 2-3 tablespoons or 30 mL per day. Higher intakes like 60 mL or more daily provide no extra blood pressure benefit.
Consuming olive oil as part of the Mediterranean diet provided the greatest reductions in clinical trials – up to 4 tablespoons or 60 mL daily. But in this eating pattern, olive oil replaces other less healthy fats instead of simply being added to your regular diet.
Experts recommend getting no more than 35% of your total daily calories from fat. If you currently eat a high fat diet, be mindful of cutting back on other sources of saturated and trans fats when increasing olive oil intake.
Risks or Side Effects
Olive oil is highly safe for most people and associated with minimal risks when used in moderation as part of a balanced diet. Potential side effects can include:
– Allergic reactions in those with olive or olive pollen sensitivities – symptoms may include rash, itching, swelling, and breathing problems.
– Loose stools or diarrhea – some people may experience GI upset, especially with high intakes of olive oil on an empty stomach.
– Weight gain – olive oil is high in calories at around 120 calories per tablespoon, so excess intake without cutting back elsewhere could lead to weight gain.
– Interactions with medications – very high intakes may potentially impact absorption or efficacy of a few medications. Talk to your doctor.
As with any dietary fat, it’s also important to be mindful of your total calorie intake when increasing olive oil. But for most people, incorporating around 2 tablespoons of olive oil daily can be safe and beneficial.
Quality and Storage
To retain the highest quality and reap maximum benefits from olive oil:
– Choose extra virgin olive oil in dark glass or metal containers to limit light exposure.
– Check for a harvest or best by date and pick newer batches. Consume within 1 year of harvest.
– Store in cool, dark place and once opened, use within 3-4 months. Heat, light and oxygen degrade olive oil.
– Buy smaller bottles you can use up quicker once opened. Larger tins have more air exposure.
– When cooking, use lower heat to retain nutrients and prevent oxidation. Unheated olive oil retains the most benefits.
– Smell and taste olive oil before buying – fresher, better quality has more peppery, bitter notes versus rancid, musty flavors.
Should You Take Olive Oil Supplements?
While dietary supplements containing olive oil or olive oil extracts are marketed for heart health, evidence does not support use of these supplements for lowering blood pressure or in place of dietary olive oil.
Reasons olive oil supplements may not provide the same effects as eating real olive oil include:
– Bioactives like polyphenols are likely modified or lost during processing and encapsulation used to make supplements.
– Synergies between oil components are important, and taking one or two compounds in isolation may not work the same.
– Obtaining oil in food form, especially unheated, may be superior for absorbing fat-soluble nutrients.
– Higher doses do not equate to increased benefits – oil supplements often provide way more than the optimal daily amount.
For these reasons, it’s best to meet recommendations for olive oil intake by incorporating quality extra virgin olive oil into cooking, salads, dips, marinades, and other dishes. Supplements are an unnecessary cost.
The Bottom Line
In summary, research suggests olive oil can produce modest but clinically relevant reductions in blood pressure in people with normal blood pressure, prehypertension, or existing hypertension. The benefits are most evident when olive oil is consumed as part of a Mediterranean style diet rich in fruits, vegetables, legumes, whole grains, fish, nuts and healthy fats.
The optimal daily intake for blood pressure benefits appears to be around 2-3 tablespoons of extra virgin olive oil. Incorporating olive oil may also provide broader cardiovascular and metabolic health advantages. But be mindful of overall calorie intake when increasing olive oil consumption. For most people, using olive oil as recommended can safely help lower elevated blood pressure.