I’ve always loved the taste and aroma of olive oil. Add crushed garlic, a sprig of rosemary, and a pinch of red pepper flakes—then drizzle it over a fresh green salad. What comes with all that tasty goodness? Heart health. I love to remind myself—and anyone at the dinner table—of this happy coincidence any chance I get.
What Makes Olive Oil So Heart Healthy?
Olive oil’s heart health benefits come from its unique combination of healthy monounsaturated fats and powerful antioxidants known as polyphenols, both of which help to block the oxidation of LDL cholesterol. Remember, the oxidation of LDL cholesterol fuels inflammation, which in turn causes coronary heart disease. So, protecting LDL cholesterol from oxidation is a crucial step in preventing atherosclerosis ("hardening" of the arteries). Plus, several important studies on olive oil for heart health inspired me to put it at the top of my list of heart healthy foods. The first study, published in BMC Genomics (April 2010), found that olive oil may impact gene expression to halt inflammation. Since inflammation—not cholesterol—is the real cause of heart disease, this research immediately caught my attention.
For this study, researchers recruited 20 people with metabolic syndrome—a condition that’s linked to type 2 diabetes, heart disease, and premature death. For six weeks, the participants ate a breakfast that contained olive oil that was either low in phenolic compounds, or one that was high in phenols. They took blood samples after meals to check for the expression of over 15,000 human genes. What they found was that for those eating the high phenol olive oil, 79 genes were suppressed—including the genes linked to inflammation.
Plus, a Second Study Found Olive Oil Can Prevent Heart Attacks & Strokes
The PrediMed (Prevencion con Dieta Mediterranea) trial, which was published in the New England Journal of Medicine, revealed the biggest news yet about olive oil for heart health.
For their trial, the researchers selected over 7,000 participants without cardiovascular disease who were considered “high risk” for a cardiovascular event in the future. They assigned the participants to one of three groups. One group consumed about 4 tablespoons of extra virgin olive oil per day. Another ate 30 grams of mixed nuts (almonds, walnuts, and hazelnuts) daily. The third group received no special foods, but dietary advice to eat a low-fat diet.
The average follow-up time was 4.8 years. What the investigators found is that both the olive oil and mixed nuts group had a 28 to 30 percent reduction in cardiovascular events, including heart attacks and strokes.
Blood Pressure Relief, Too!
There’s more good news about olive oil for heart health. A Spanish study showed that systolic and diastolic blood pressures fell by approximately 8 mm/Hg on an olive oil diet, compared to those using sunflower oil. Plus, in animals, olive oil led to an enhanced relaxation of the aorta and was successful in treating rats with high blood pressure.
So, if you’re already eating a Mediterranean diet, like my Pan-Asian Modified Mediterranean Diet, you could kick it up a notch by downing a tablespoon of olive oil three times a day like I do.
What is the Healthiest Olive Oil?
As you likely know, store shelves are packed with a variety of olive oils that come in different flavors, textures, styles, and the like, and choosing one can be frustrating—even confusing.
This is an olive oil dilemma I’ve faced myself. Years ago, enthralled by the health perks of extra-virgin olive oil, I took pleasure in acquiring cold pressed extra virgin olive oil from countries around the world. But then I learned that much of the olive oil we buy is laced with other oils. For example, some olive oils are mixed with canola oil made from rapeseed oil, which is considered toxic by many experts. Plus, some olive oils are made with GMOs.
The final straw for me was a University of California at Davis study, which tested eight major brands, and 124 samples, of extra virgin olive oil—and more than 70% failed! Plus, I discovered that to carry the extra virgin olive oil label in Europe a product only needs to contain 75% extra virgin olive oil.
The healthiest olive oil is pure extra virgin olive oil, because it’s higher in health-promoting polyphenols than other olive oils. But if the one you’re buying isn’t pure extra virgin olive oil, you risk ingesting oxidized fats and free radicals that can damage your cells.
How Do You Spot Pure Olive Oil?
Some of the best advice I found came from Carole Firenze, author of Passionate Olive: 101 Things to Do with Olive Oil. Because olive oil is highly vulnerable to air, light, heat, and time, when you’re looking for pure olive oil you should look at these things:
- Storage: Extra virgin olive oil must be stored in a dark glass container away from heat and light. If you buy a large bottle, and don’t plan on using it all in the next few weeks, separate out a smaller bottle’s worth for the cabinet and refrigerate the rest. When it’s time to refill, take out the refrigerated bottle a few hours ahead of time to allow it to uncoagulate.
- Harvest Date: Look for a harvest date and select an olive oil that was made from this year’s harvest.
- Traceability: Read labels carefully, noting where the olives originate—including the country, state, province, or local area. If you know nothing about the mill or producer, look for seals of authenticity from certification agencies such as the California Olive Oil Certification (COOC) or DOP and IDP (Italian certifications). According to Firenze, traceable olive oils are more likely to be authentic.
- Final tips: I’m most confident about organic extra virgin olive oils from California with the COOC seal. I also check the expiration date and follow the pointers I listed above. Plus, I observe where the extra virgin olive oil is in the store, ensuring that it’s stored away from light and heat. I’ve also tried extra virgin olive oils from local growers.
When selecting an olive oil, remember that light olive oils are usually used for cooking up to 130 degrees (above this temperature, olive oil can become more saturated), because they tolerate heat much better. The more deeply hued, thicker extra virgin or virgin olive oils are often preferred for salad garnishing, since they are generally tastier. Plus, using unheated olive oil fully preserves its monounsaturated quality.
Also, keep in mind that while olive oil is good for heart health, it does contain 14 grams of fat per tablespoon—so the calories can certainly mount if used too liberally. That said, olive oil can boost the flavor and heart healthy quality of all kinds of entrée and vegetable recipes. Just be sure to store your olive oil in a glass container, because plastic can contain the heavy metal cadmium, which will leach into the oil, and the joints of metal containers are soldered with lead, which can also contaminate the oil.