We all know olive oil is a common ingredient in a healthy diet, and Time magazine even named the olive as one of its "50 New Healthiest Foods of All Time" in 2015.
But just how healthy is olive oil?
We may never resolve all the mysteries surrounding olive oil, but there are some undisputed facts about this elixir. Here are five tested truths about olive oil:
Olive oil truth no. 1: It offers numerous unique health benefits.
While it's counterintuitive that olive oil, with its high fat content, would be healthy, that's the case, Katherine Zeratsky, R.D., L.D. stated on the Mayo Clinic health consumer website. "The main type of fat found in all kinds of olive oil is monounsaturated fatty acids (MUFAs), which are considered a healthy dietary fat," Zeratsky said. "If you replace saturated and trans fats with unsaturated fats, such as MUFAs and polyunsaturated fats (PUFAs), you may gain certain health benefits."
Olive oil's MUFAs and PUFAs can help lower the risk of heart disease by improving risk factors −lowering total cholesterol and LDL cholesterol levels, for example. Other research shows that MUFAs may benefit insulin levels and blood sugar control, a benefit for those who have or are at risk of developing Type 2 diabetes.
But don't go too far with this idea, warned Zeratsky, noting that even healthier fats like olive oil are high in calories and should be used in moderation.
Olive oil truth no. 2: Virgin olive oil can knock out bacteria that antibiotics can't.
While olive oil has long been known as a heart-healthy product, microbiologists at the University Hospital of Valme in Seville, Spain, have determined that it fights bacteria in the stomach, too. The study, reported in Prevention, combined virgin olive oil and H. pylori, a bug that causes most peptic ulcers and even some types of stomach cancer, in a test tube full of the same type of acid found in the stomach. According to the study's results, the oil knocked out eight different strains of the powerful bacteria, three of them bacteria that don't yield to antibiotics couldn't defeat.
Olive oil truth no. 3: Extra virgin olive oil can curtail after-meal blood glucose spikes.
Diabetics with after-meal blood glucose spikes might want to try extra-virgin olive oil, according to a study reported in Diabetes Journal and publicized by the American Diabetes Association. Researchers found that EVOO reduced glycemic response to a high-glycemic index meal in patients with Type 1 diabetes. Researchers noted that when patients ate a high-GI meal, they experienced a rise in glucose levels soon after eating if the meal contained butter or was low in fat. But when the high-GI meal was prepared with EVOO, there was not a steep rise in blood glucose level.
This is definitely great news for people with Type 1 diabetes, and the finding could lead to even more research into the health benefits of a diet that includes EVOO.
Olive oil truth no. 4: EVOO can kill cancer cells.
One of the most momentous benefits of olive oil may end up being its impact on cancer. From a study made public in January 2015, published in the journal Molecular and Cellular Oncology and reported in Olive Oil Times, we already know that an ingredient in EVOO can kill cancer cells.
Nutritional scientist Paul Breslin (Rutgers University), biologist David Foster (Hunter College) and chemist Onica LeGendre (Hunter College) discovered in a lab study that an olive oil component called oleocanthal causes a rupture of a part of the cancerous cell. This action releases enzymes and causes cell death without harming healthy cells, in effect killing cancer cells with their own enzymes.
"Oleocanthal is a name for a chemical in extra virgin olive oil (EVOO) that means 'Stinging Oil Aldehyde'," Breslin told Olive Oil Times. "It is made by the olive when it is crushed to make the pulp from which the oil is pressed."
Olive oil truth no. 5: Lots of "extra virgin" olive oils aren't so virgin, but you can still choose a good one.
The report determined that 69 percent of imported olive oil samples and 10 percent of California olive oil samples labeled as extra virgin failed to meet the IOC/USDA standards for extra virgin olive oil and the study is still being cited.
Of course, it doesn't change the truth about the many health benefits and disease-fighting properties of EVOO. But it should make consumers extra careful about where they buy EVOO, according to Pam Skea, managing director of Flying Olive Farms, who was quoted in Raleigh Magazine.
Skea said one way to circumvent EVOO content concerns is to identify a single-sourced olive oil with traceable origins, choosing an EVOO from a smaller distributor who lists dates of harvest and country of origin on the label.