Many researchers have suggested a Mediterranean diet that focuses on mostly plant-based meals, with dishes like black bean vegetarian chili and whole wheat penne pasta with roasted vegetables, can reverse even severe coronary artery disease, along with slowing or reversing early stage prostate cancer, and the progression of Type 2 diabetes.
According to Dean Orish, a clinical professor of medicine at the University of California, San Francisco, and the founder of the Preventive Medicine Research Institute, claims an optimal diet is low in unhealthful carbs (both sugar and other refined carbohydrates) and low in fat (especially saturated fats and trans fats) as well as in red meat and processed foods.
A study published earlier this year in the New England Journal of Medicine concluded that a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events.
Some ate a low-fat diet, another group ate a Mediterranean diet with nuts. And a third group ate a Mediterranean diet that included almost four tablespoons of extra-virgin olive oil per day.
Researchers discovered a Mediterranean diet rich in olive oil or nuts cut the risk of heart attacks and strokes by 30 percent.
“The fact is, there are a huge range of benefits of real extra-virgin olive oil,” notes Tom Mueller.
Mueller spent six years investigating olive oil, and says olive oil is good for two reasons: it’s high in unsaturated fat, and extra-virgin oil, which is the highest-grade and least-processed form of olive oil, contains other beneficial plant compounds called polyphenols.
Mary Flynn, an associate professor of medicine at Brown University, says Olive oil is a very healthy food. “I consider it more medicine than food.”
Beware of Low-Grade Olive Oil
NPR’s Allison Aubrey notes more than half of the extra-virgin olive oil imported into the U.S. is substandard.
A study from the University of California, Davis, found that 69 percent of imports tested failed to meet a U.S. Department of Agriculture quality standard.
“The fact is, it’s quite often just very low-grade oil that doesn’t give you the taste of the health benefits that extra virgin should give you,” Mueller says, and adds in some cases the oil is too old.
“By the time imported olive oil reaches us, it has often been shipped from place to place and sometimes not stored well. Even if it’s not noticeably rancid, many of the heart-healthy compounds have degraded and fizzled.”
Mueller characterizes extra-virgin olive oil as a fresh-squeezed juice. “It’s a fruit juice — therefore freshness is a critical question,” he says, and warns the FDA no longer extensively monitors olive oil imports to ensure producers meet quality and freshness standards.
Where To Get Quality Olive Oil
Mueller suggests looking for brands that carry a harvest date on the bottle. California Olive Ranch oil has a date clearly stamped on the back of the bottle.
Gregg Kelley of California Olive Ranch says every bottle produced by his company includes the date olives were harvested to produce the oil in the bottle, and says the olives were quickly pressed so the oil is fresh.
“The most important thing for consumers to remember when they’re purchasing extra-virgin olive oil is that it is not wine: It does not get better with age. It’s never better than the day it was produced,” Kelley says.
Properly storing olive oil preserves its freshness, but as soon as the bottle is opened and the oil is exposed to oxygen and light, it will begin to degrade.
Several factors play a role in how fast olive oil spoils, such as the variety of the olives, and how the oil is produced and stored.
Selena Wang of the UC-Davis Olive Center suggests olive oil is no longer good after four to six months after opening.
Mueller explains that oils with the highest levels of heart-healthy compounds are inclined to be pungent and peppery, and he says if the oil slightly stings the back of your throat then the beneficial polyphenols are there.
Once you have that taste, you get used to the bitterness and pungency, you never go back, says Mueller. “It’s a completely different experience.”
“I grew up with terrible oil; I had a huge tin in my grandparents’ cabin and that was olive oil for me — it was moldy and fusty and there for years,” he says.